# Power steering/Alt brackets 389 vs 400



## ragtopgoat (Sep 26, 2019)

I have a '66 GTO, with power steering, no A/C or air pump (the car is a recent acquisition). The previous owner upgraded it to a 400CI engine from a '67, but it appears that he used the brackets from the 389 on this engine. I'm beginning to suspect this might be causing me problems, as I'm having problems with aligning the pulleys/belts between the PS and alternator. The alternator just died and I bought a replacement Powermaster from Summit. The dimensions are nearly identical to the alt that I'm replacing (https://www.summitracing.com/parts/pwm-47293/applications/make/pontiac/model/gto). It's a 12SI alternator. But now that I have it installed, the alternator belt is basically touching the power steering pulley. With the alternator that I replaced (Delco Remy, not sure but I think it's the original that came with the car) the alt belt was close to the PS pulley, but with this replacement alternator, it's too close. So my question is, is it possible that using the 389 bracketry on the 400 engine is not working? Should I cut bait and replace the PS/alt bracket with the '67 bracket? Also, the alternator strap is bolted to the thermostat housing and attaches to the front of the alternator (you can see the nut doesn't fully engage the stud threads). Is that correct? Should it mount behind the alternator? A picture is worth a thousand words:










Note how close the alternator fan blades are to the alternator strap (I actually ground off some material to create some space). 

The bracket that I have attached to the driver's side head:









According to the Ames catalog, it should be this for a '67 400CI engine:










Sorry for the lengthy post, but I suspect that it is a problem using brackets from a '66 389 engine on a '67 400 engine. I am looking to the experts on this forum to help me out here. 

Thanks!


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## BLK69JUDGE (Jun 10, 2010)

uhhhhh

fairly sure the alternator adjust strap goes on the rear of the alternator
and 2 of em somebody hammered that one to fit


1966 gto tripower alternator brackets - Google Search


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## O52 (Jan 27, 2019)

And there should be two brackets for a PS car. One attached to the water pump, the other to the thermostat.


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## LATECH (Jul 18, 2018)

The crankshaft on a 389 is like 3/16 of an inch difference in length than a 400. That is what is giving you fits.The balancer goes on to a different depth. throwing belt alignment off when using the earlier 389 bracketswith a 400

I could be wrong about this.I am still looking.


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## O52 (Jan 27, 2019)

Hmmm Looks like a Tri-Power. Shouldn't make a difference from what LATECH said however.


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## LATECH (Jul 18, 2018)

Well,it appears as though 63 and back had a shorter crank snout of 3 inch. 64 up was 3.5 inch.
That could possibly mean a different depth of the hub of the balancer. I had some issue with my 389 and the brackets as well, I just dont remember the exact finding at the moment.I had to use a few flat washers to shim the alternator and PS pump to get the belts to line up.
I will keep looking to see if I can find an answer.
Early balncer ,later brackets. Seems the water pump for the 11 bolt timing cover setup and the 8 bolt setup had a diffence in shaft lentghs as well. 
I have a 65 389, with the 11 bolt timing cover, that may help add to the problem , as the pre 68 should have an 8 bolt, which would change the water pump shaft length/offset for the fan / pulley hub in relation to the centerline of the crank pulley.
Could be 11 bolt cover/water pump with the early pulleys / brackets for the 389 causing the alignment issue? 

Maybe pontiac jim will step in and shed somelight here.


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## LATECH (Jul 18, 2018)

A small part of the problem here also is that the alternator belt should be a 3/8 wide belt, not 7/16


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## LATECH (Jul 18, 2018)

052 shows his alternator top bracket asbolting to the rear of the alternator which is correct. If you look though, he has a 4 barrel setup, not a tri power. Your top bracket goes to the thermostat housing.That is incorrect.

That is the wrong top bracket, bolted on in the wrong location, at both ends...LOL

Blue Charcoal 1966 GTO Hardtop - UltimateGTO.com

Look at this tri power setup ^^^^^^^^^^ It clearly shows the engine end of the bracket to thewater pump.

Also note that he has the passneger side valve cover on backwards. LOL

The drivers side gets the hump in the rear, the passenger side , the hump goes in the front.


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## LATECH (Jul 18, 2018)

Montero Red 1966 GTO Hardtop - UltimateGTO.com


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## ragtopgoat (Sep 26, 2019)

BLK69JUDGE said:


> uhhhhh
> 
> fairly sure the alternator adjust strap goes on the rear of the alternator





O52 said:


> And there should be two brackets for a PS car. One attached to the water pump, the other to the thermostat.
> 
> View attachment 134147


My thermostat housing is mounted vertically on front of the crossover, so that bracket wouldn't work. Is it possible that the bracket on my car is supposed to be the supporting bracket to the straight piece coming off of the water pump bolt (both then bolting the rear of the alt)? 
One question I have, the stud and nut on the top of my water pump is too short to mount anything to. From the image below, you can see that it isn't long enough to fully engage the nut that's on it. Is it possible to replace that stud with a longer one without compromising the water pump seal?


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## ragtopgoat (Sep 26, 2019)

LATECH said:


> 052 shows his alternator top bracket asbolting to the rear of the alternator which is correct. If you look though, he has a 4 barrel setup, not a tri power. Your top bracket goes to the thermostat housing.That is incorrect.
> 
> That is the wrong top bracket, bolted on in the wrong location, at both ends...LOL
> 
> ...


From both of those picture, it appears to be just a single bracket to the alternator. Is that missing the second piece? I'm trying to figure out what I need to correct this setup. 
If I'm reading the Ames catalogue correctly, it appears what I need are parts #N142AD and #N142A.


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## LATECH (Jul 18, 2018)

Of all the tri powers I have seen, they use one bracket.


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## LATECH (Jul 18, 2018)

ragtopgoat said:


> From both of those picture, it appears to be just a single bracket to the alternator. Is that missing the second piece? I'm trying to figure out what I need to correct this setup.
> If I'm reading the Ames catalogue correctly, it appears what I need are parts #N142AD and #N142A.


Looks like that is the case.Most guys must be missing the second piece.


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## LATECH (Jul 18, 2018)

And then there is this on, which does in fact show 2 brackets for the alternator. One is bolted to the w pump and the other is on the thermostat stud.Black 1966 GTO Convertible - UltimateGTO.com

Looks like the stud in your housing may be short.


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## LATECH (Jul 18, 2018)

The two brackets effectively triangulate the bracket system.It is a good thing. It will keep the alternatr form shaiking around at High rpm.That can cause belts to fly off.

2 brackets. I learned something today.


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## LATECH (Jul 18, 2018)

I am still concerned about the pulleys lining up. Not sure if the bracket on the head is different so that it changes the offset from the water pump/crank pulleys, or if your problem is with the offset of the water pump flange and the offset built into the different pullys between the 2 years and bracket setup.
I do know this seems to be a common problem for a lot o guys when putting a drive setup on a motor from pieces they find.


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## RMTZ67 (Mar 12, 2011)

Are you sure that's a 400? Or maybe a 400 w/ 389 intake.....if that would fit???


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## ragtopgoat (Sep 26, 2019)

I checked the pulley alignment, best I could with a straight edge. The alt pulley and PS pulley seem to line up pretty well with the water pump pulley. The w-pump and crank pulleys are off by a 1 mm.


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## ragtopgoat (Sep 26, 2019)

RMTZ67 said:


> Are you sure that's a 400? Or maybe a 400 w/ 389 intake.....if that would fit???


When I bought this car, it was listed as having been upgraded to a 400 from a ‘67. I would be shocked if it turned out to be a 389. The PHS report shows it originally came with a 4 bbl carb, so the intake and three carbs were not OEM. I don’t know if they were originally installed on the 389 or sourced for the 400. I assume they were part of the 400 upgrade.


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## BLK69JUDGE (Jun 10, 2010)

fairly sure 

you can interchange a 66 and a 67 power steering pump
BUT
each unit has to be complete ... because they are total different brackets and pump housing
66 and 67 water pump and crank pulleys are the same dimentions... and not have the same part numbers

the issue he has is the adjuster hits the fan on the alternator because somebody used a hammer and the vise to masage the one single one he has
to make it fit on the wrong side of alternator

I would
buy 2 new brackets and install..... job done ....

n142a and n141ad ames performance .......... Ames Performance Engineering, Classic GTO Parts, Firebird Parts, and Full Size Pontiac restoration parts.

page 213 in catalog 35 engine accessorie brackets


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## ragtopgoat (Sep 26, 2019)

BLK69JUDGE said:


> fairly sure
> 
> you can interchange a 66 and a 67 power steering pump
> BUT
> ...


I will order these parts as I want this installation to be sound. Question I have is, the two studs that the brackets mount to (thermostat housing stud and top water pump stud), as you can see in the picture above, they are too short. Can I remove and replace those studs without disrupting the seals? If possible, it would be nice if I could carefully remove each of them and install a longer one without having to re-gasket/reseal. Thoughts?


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## ragtopgoat (Sep 26, 2019)

After staring at the pulleys and belts, I suspect that the alignment problem has more to do with the power steering pump than the alternator. I just had the PS pump rebuilt and reinstalled it. I found that the pump did not have the cup washer behind it, so I ordered one and attempted to install it. But the stud on the rear of the ps-pump is too short. It's roughly 3/4" long, the bracket that it extends through is 1/2" thick, which barely leaves enough for a washer and nut, let alone fitting the cup washer in. I left out the cup washer and put it back together the way it was, but now I'm thinking that the cup washer would push the ps-pulley forward a bit, helping to clear the alternator belt. I'm not sure if there are options for different lengths of this ps-pump stud, but I haven't been able to source any at all. Any advice as to where I can find a longer ps-pump stud?


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## BLK69JUDGE (Jun 10, 2010)

just making sure you have the cup over the nut ...

here are 3 different lengths ,,, 

I like the 1" also ,,, 3/4 is original and they had a super thin washer and a split lock nut


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## ragtopgoat (Sep 26, 2019)

So when I acquired the car, that cup washer was missing. I ordered it and found the stud on the back of the ps-pump too short to use it. As mentioned above, not having that cup washer in place affects the alignment of the alt and ps pulleys, not to mention it helps with the adjustment of the ps-pump and belt tensioning. What I'd like to know is where do you source those different lengths of studs? I've been looking and have not had much luck. 
ALSO, is there anything to be aware of when swapping out that stud? I've heard that there is an o-ring inside that blind hole, that is held in place by that stud. I want to make sure I'm not going to have ps fluid gushing out when I remove it, as I'm going to swap the stud in-place.


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## LATECH (Jul 18, 2018)

The o ring is held in place by a machine recess in the body of the pump itself. As long as you dont disturb the can (reservoir) the O ring will stay put for you. easy. Just remove the stud you dont want, reinstall the stud you do want.It will drip some fluid, but it wont be a geiyser. Just dont waste time getting the new one in there.


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## BLK69JUDGE (Jun 10, 2010)

never swapped one out with fluid in the reservoir ..... it may weep a little

an old turkey baster always comes in handy around now also

they are spares off of other power steering pumps I have taken apart ....

[email protected]

Scott


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## PontiacJim (Dec 29, 2012)

LATECH said:


> Well,it appears as though 63 and back had a shorter crank snout of 3 inch. 64 up was 3.5 inch.
> That could possibly mean a different depth of the hub of the balancer. I had some issue with my 389 and the brackets as well, I just dont remember the exact finding at the moment.I had to use a few flat washers to shim the alternator and PS pump to get the belts to line up.
> I will keep looking to see if I can find an answer.
> Early balncer ,later brackets. Seems the water pump for the 11 bolt timing cover setup and the 8 bolt setup had a diffence in shaft lentghs as well.
> ...


OK, let's sort this out. The early 389 crank snout is indeed shorter but I believe this was changed, as stated, in 1964. So here is a 1964-65 timing cover. Pic #1

1966-67 used the 8-bolt cover, different timing scale. Pic #2

The 1966-67 balancer is a 2-piece, 6-bolt deal. Pic #3.

1968 timing cover is a one year only, 8-bolt cover. Pic #4, and the 1968 & up 1-piece balancer. Pic #5

1969 & up used this 11-bolt timing cover. Pic #6

The '68 engine with 8-bolt cover used a 4" long water pump shaft which was also carried into early 1969 on the 11-bolt cover (which can leave people scratching heads as most replacement's are 4.5" and the 4" for '69 is not often listed). Later '69 water pumps used a 4.5" long water pump shaft. Pic #7

So first off is to ID the timing cover & balancer to make sure it is 1966-1967 pieces. I used my 1968 PS/Alt brackets on a '72 engine and the pulleys did not line up. The brackets are for the 4" water pump, so I improvised with washers and longer grade 8 bolts to get the bracket to where I needed it to be to line up with the '72 water pump/balancer pulleys. So brackets need to be correct as has been pointed out.

Pic #8 shows the correct pulley/belt arrangement. Note the Alt has 2 straps holding it at the top. One goes to the water pump bolt, the other goes to the water neck outlet stud.

Pulleys per the Restoration Guide:

1966 & 67 balancer - 2-groove 7 1/4" diameter
1966 Part #9783144
1967 Part #9786714

1966 & 67 PS - 5 7/8" diameter
1966 Part #9777401
1967 Part #9786900

1966 & 67 Alt - 2 3/4'
1966 & 67 Part #1949357

Water Pump - 2-groove 8" diameter
1966 Part #9778808
1967 Part #9786819

1967 Belts. The correct AMA specs for belts are, Fan/Water Pump/PS - 53.5", .47" width, 36 degree angle of the V on the belt. Alternator - 61.2", .38" width, 36 degree angle of the V.

Click on the pics will enlarge them if needed.


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## RMTZ67 (Mar 12, 2011)

Yours seems to be a 389, which also takes two brackets to the rear of the alternator. O52 is a 400 with the water neck on top.The correct 67 alternator bracket is the lower one in your pics. inline tube part# you probably need SKU:INL14829 which are two brackets, Could you (just get two/four nuts that are 1/2 size thinner from Ace hardware?) My bad...I was thinking you wanted longer studs for the pump brackets.


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## ragtopgoat (Sep 26, 2019)

I have an 8 bolt timing cover, the balancer is 7 1/4" diameter, 6 bolt with a part #9778804 stamped on it. This is a 400 engine from a '67, with a tri-power intake and carbs from an unknown source. Here's a pic of the balancer with the number stamp:


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## ragtopgoat (Sep 26, 2019)

I just pulled this off the motor with my phone camera, difficult to reach, but tell if this is the date code? It looks like "C248". March 24, 1968? Maybe I'm not reading that correctly.


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## PontiacJim (Dec 29, 2012)

ragtopgoat said:


> I just pulled this off the motor with my phone camera, difficult to reach, but tell if this is the date code? It looks like "C248". March 24, 1968? Maybe I'm not reading that correctly.
> View attachment 134188


C246 - March 24, 1966

That is a 389 engine. Block Casting 9778789

The former owner may have bored it .060"over and used 400CI pistons, thus the 400CI claim? But it is not a 1967 engine. 1967 GTO engine will have the "670" casting on the middle exhaust port. Again, if using 400CI pistons, you can use any 1967 & up head.


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## ragtopgoat (Sep 26, 2019)

Well that is interesting. I will have to reach out to the previous owner and find out what the story is.


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## LATECH (Jul 18, 2018)

Wow. Thats good info Pontiac Jim.I learned something more today.
I was una ware of an 8 bolt 1968 only timing cover . I see it has the port shape for the 2 plate setup/.
Good Info.Thank you.


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## Lemans guy (Oct 14, 2014)

I know you are trying to keep your car all original. But for those who are not,...just a note.

I got tired of messing with all those floppy brackets over the years anytime PS or Alt needed service, and I drive the car quite a bit, so I changed to a serpentine belt system made BY CVF Racing specifically for the Pontiac 400 engine.

I can change my alternator on the road, all the work is on top and the belt is tensioned by a threaded rod, very easy no pulling and holding and trying to get it tight, no dropping all those little bolts and studs etc. and trying to get that one underneath. I always put the car on the lift for that one.

Still just a 400 engine carb and distributor, not FI or LS or anything, but a serpentine belt.

So some might want to consider it, Chexk CVF Racing nice stuff and good prices.


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## ragtopgoat (Sep 26, 2019)

Thanks for all the excellent advice and help with this. Clearly I'm still learning about this car and engine. 
A follow up question, I will need to replace the top water pump bolt with something that can mount the alternator bracket that I have ordered. As near as I can tell (I don't have much to measure them by), it looks like a 5/16" x 18 stud or bolt. Should I just replace the stud/nut with a hex bolt that's long enough to hold the alt-bracket? Or is there a source for longer studs to accommodate the bracket? Looks like it should be relatively easy to remove that one stud and replace it without disturbing the water pump housing and seal:


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## BLK69JUDGE (Jun 10, 2010)

I have the correct bolt with stud for the adjuster strap at the thermo housing
I also have the longer water pump bolt for the other strap to the water pump

is that a nut on a stud on the water pump at the top in the last picture?

Scott


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## ragtopgoat (Sep 26, 2019)

BLK69JUDGE said:


> I have the correct bolt with stud for the adjuster strap at the thermo housing
> I also have the longer water pump bolt for the other strap to the water pump
> 
> is that a nut on a stud on the water pump at the top in the last picture?
> ...


Yes, it is. I think you can see that the stud that's on there now is really too short, as the nut is not fully engaged. Is that a bolt instead of a stud that you have to mount the strap on top of the water pump?


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## BLK69JUDGE (Jun 10, 2010)

yes ,,, thats probably why its broken ,,, it only had 1 upper bracket and vibrated and snapped off the head
that bolt is 3/16 ish longer than the others ,,,, thats going to be a bit of an issue being busted,,, 
probably time to pull the water pump check impeller clearance and make sure you have a quality correct impeller on the back of the pump, and get that bolt extracted ..... so the new strap hasthe correct mount location


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## Jerry H. (Mar 19, 2020)

Wait a minute. Is everyone not overthinking this problem? The OP states he replaced the bad alternator. IF the original alternator lined up and worked, then the replacement alternator is wrong or it is reinstalled wrong. And the strap is on the wrong side of the mount on the alternator.


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## EdGorman (Mar 26, 2020)

ragtopgoat said:


> I have a '66 GTO, with power steering, no A/C or air pump (the car is a recent acquisition). The previous owner upgraded it to a 400CI engine from a '67, but it appears that he used the brackets from the 389 on this engine. I'm beginning to suspect this might be causing me problems, as I'm having problems with aligning the pulleys/belts between the PS and alternator. The alternator just died and I bought a replacement Powermaster from Summit. The dimensions are nearly identical to the alt that I'm replacing (PONTIAC GTO Powermaster Street Alternators 47293). It's a 12SI alternator. But now that I have it installed, the alternator belt is basically touching the power steering pulley. With the alternator that I replaced (Delco Remy, not sure but I think it's the original that came with the car) the alt belt was close to the PS pulley, but with this replacement alternator, it's too close. So my question is, is it possible that using the 389 bracketry on the 400 engine is not working? Should I cut bait and replace the PS/alt bracket with the '67 bracket? Also, the alternator strap is bolted to the thermostat housing and attaches to the front of the alternator (you can see the nut doesn't fully engage the stud threads). Is that correct? Should it mount behind the alternator? A picture is worth a thousand words:
> 
> View attachment 134140
> 
> ...


Have you tried taking the pully off the alternator and put the one from the old alternator on it. The summit one looks thicker on the back side than an original pully


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## PontiacJim (Dec 29, 2012)

Jerry H. said:


> Wait a minute. Is everyone not overthinking this problem? The OP states he replaced the bad alternator. IF the original alternator lined up and worked, then the replacement alternator is wrong or it is reinstalled wrong. And the strap is on the wrong side of the mount on the alternator.


Agreed in part, but the poster was not sure about his pulleys/brackets, 

"With the alternator that I replaced (Delco Remy, not sure but I think it's the original that came with the car) the alt belt was close to the PS pulley, but with this replacement alternator, it's too close. So my question is, is it possible that using the 389 bracketry on the 400 engine is not working?"

So yes, the replacement ALT may be wider, but making sure the correct/matching brackets are being used is also part of what needs to be checked and/or replaced. Once that is done, then if the alignment is off, I'm on board with the alternator being too large. However, I think the ALT at the bottom bolt could be altered to move in/out a slight amount by grinding or adding a shim/washer.


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## Gtowally (Jan 19, 2019)

That brackets wrong. Get the correct 2brackets. 1 bolts to the water pump the other 2nthe thermostat housing, and they both bolt on to the alt via a bolt on the back of the boss on top of the alt


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## Gremlin66 (Oct 11, 2009)

I’m sorting through the same thing on my 66. The block is a 1970 RAIV. I have a 1965 timing cover as there was a non original tripower that came on the car that I still have but currently not using. It has a Holley spreadbore and edelblock manifold. 

Harmonic balancer is the the two piece, six bolt and the pulley is an aftermarket 3 groove from Ram Air Restorations since I added aftermarket A/C. The water pump pulley grooves line up well with the crank pulley grooves. 

I have the same P/S pump and bracket as the OP. Also installed new Powermaster alternator as the OP did. Alternator, water pump and crank pulleys line up well but I have the same issue with the alternator belt being close to the water pump pulley and belt. I realized I didn’t have the cupped washer on the PS stud. I played with some shims until the cupped washer comes and I think it will do the trick. If it doesn’t I think shimming it with some washers will do the trick.

I can get some pictures of my setup later if that would be helpful. Forgot to mention I have the two brackets on the back of the alternator that I remember ordering from Ames.


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## ragtopgoat (Sep 26, 2019)

PontiacJim said:


> Agreed in part, but the poster was not sure about his pulleys/brackets,
> 
> "With the alternator that I replaced (Delco Remy, not sure but I think it's the original that came with the car) the alt belt was close to the PS pulley, but with this replacement alternator, it's too close. So my question is, is it possible that using the 389 bracketry on the 400 engine is not working?"
> 
> So yes, the replacement ALT may be wider, but making sure the correct/matching brackets are being used is also part of what needs to be checked and/or replaced. Once that is done, then if the alignment is off, I'm on board with the alternator being too large. However, I think the ALT at the bottom bolt could be altered to move in/out a slight amount by grinding or adding a shim/washer.


The dimensions of the Powermaster alternator are shown on the SummitRacing website (https://static.summitracing.com/global/images/prod/xlarge/pwm-17294_sn_xl.jpg?rep=True), and I did as accurate measuring of the original alternator that came out and they are exactly the same. The main difference is in the pulleys, the Powermaster alt has a more stout pulley. But I agree, getting the proper alternator brackets and mounting it the way it was intended is important. Given the way it is mounted now, I wouldn't trust it to hold together.


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## Gremlin66 (Oct 11, 2009)

Once I get the proper cupped washer the clearance should be better. I can also get a shorter crank/water pump/alternator belt as I have room to move the alternator torward the centerline of the motor. I believe there’s mention that the belts should be 3/8” wide, currently mine are 7/16” so that should help too. 

Not sure if it’s correct but will work for my purposes. It would be great if someone with a stock 389 could post some pictures of the belt clearances.


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## ragtopgoat (Sep 26, 2019)

Gremlin66 said:


> I’m sorting through the same thing on my 66. The block is a 1970 RAIV. I have a 1965 timing cover as there was a non original tripower that came on the car that I still have but currently not using. It has a Holley spreadbore and edelblock manifold.
> 
> Harmonic balancer is the the two piece, six bolt and the pulley is an aftermarket 3 groove from Ram Air Restorations since I added aftermarket A/C. The water pump pulley grooves line up well with the crank pulley grooves.
> 
> ...


Yep, this is my assumption as well. I have the cupped washer, but the stud on the back of my PS pump is too short. I'm waiting for a longer stud that should be here tomorrow. 
My worry is getting that top stud out on the waterpump. I'm going to attempt to extract it without removing the waterpump. Some PB Blaster in through the back of the stud hole and some careful coercion with a stud extractor. Worse case I pull the water pump and go through that.


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