# Just inherited the GTO and I've got some questions



## Pontech (Jun 19, 2016)

Less than a week ago I inherited my father's 1970 GTO. He has owned this car since before I was born and when my parents split just before I was 2 yrs old he stopped working on it and put it under cover and left it alone. I'm now 30 and looking to put it back on the road. So enough story telling. This is what I've got.

455ci bored .030 (year unknown)
Set of ported 96 heads (he said they we ram air iv heads)
Edelbrock torker pontiac 2720
Rhoads hydraulic lifters
Carter competition 750cfm 
Crane fireball cam (not sure of exact # he said he thinks it had 566 lift and 326 duration)
Pistons and Rods are unknown
Assume the bottom end is stock
Hooker headers

Muncie M22

10 bolt rear gear 4.56 (possibly 4.11 he tells me now)

My questions are:

How do I'd the block?

Are these heads any good? I read a lot about the 6x heads or even aftermarket.

Is my carb and intake still a good setup? I've read there is now a torker II and Demon carbs look like good performers.

I've worked on and revived several pickups and IH scouts... even old 70s model motorcycles. This is my first and only muscle car and I want to do it right. This car means a lot to me and any help or pointers in the right direction is so greatly appreciated.

The car is in great shape. Will try to upload photos.

Thanks guys

Josh


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## PontiacJim (Dec 29, 2012)

Looks like a clean car, and don't mess with the engine - until you know more about Pontiac engines. Suggest you do many searches through the assorted discussions. Use the "Search" feature in the upper right. Engine ID has been covered many times, as well as heads. No 96 heads are not RA IV heads, they are 1971 400CI heads, 96 CC's. Possible that they were fitted with RA IV valves, springs, 1.65 rocker arms, etc..

Factory forged rods can be the weak link in a HP Pontiac engine and it is highly recommended that they be replaced with forged rods for insurance reasons. .030" pistons probably means TRW forged pistons which were a good choice in the day, and still are. The heads and .030" over gives you a compression ratio a little over 9 to 1 which is where you want it with an iron head engine.

The 750 AFB & Torker combo were again, choices of the time as they were popular mods. The Torker was a good manifold, but loses torque/power in the bottom end, but picks it up in mid to top end power, so the gearing in the 10-bolt matches this combo.

4.56 or 4.11 gearing is way too much for a 455 CI unless running tall drag tires or possibly running 1/8 mile track -and a hell of a stoplight-to-stoplight car. Not a good daily street gear and you are losing out on the 455's torque/power band -no doubt your Dad had no problem breaking the tires loose at will. Stock rods in a 455 should not be brought past 5,200 RPM's, so you want to gear accordingly. My opinion - 3.55's would be a lot better with 3.73's getting kinda high, but probably fun.

Again, my opinion. Keep the engine/car just as Dad ran it. Freshen up the engine and add those forged rods. The car is a tribute to the era in which your Dad built the car and it is rare to find a car still intact/complete that is a throw back from his era (I can relate because this is how we built them 35 or so years ago). Very cool inheritance, cherish what it is.


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## zsowhat (Mar 7, 2016)

were you and your dad close?


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## BearGFR (Aug 25, 2008)

PontiacJim pretty much nailed it. Don't mess with the engine other than to possibly put in good aftermarket quality forged rods if they're not there already, but the rest of the engine sure sounds like whoever built it knew what they were doing, so who knows? That rear gear is too low for highway use and really, any cruising above around 50 mph. Depends on how you plan to use the car. In town (street, not freeway) and stoplight to stoplight, it'll be a blast. Open road - not so much unless you're willing to poke along at no more than 3000 rpm.

96's aren't RAIV heads, but also as mentioned they may have been retrofitted with some of the components.

You asked about getting a positive ID on the block. You need to get at least two pieces of information, and in this order: 1) 4-character date code located on the top rear of the block, hear the distributor - 1 alpha followed by 3 numerics. This will identify the model year and is important because for some of the other codes, Pontiac reused the same ones in different years to mean different things. 2) Block casting number. Usually 7 numeric digits, found on the passenger side rear of the block, "below" the head, next to the transmission mounting flange. You can web search "Pontiac Engine Codes" and find several sites that tell you how to decode them, and/or you can post them here. Also, the two character engine code on the passenger side front of the block just below the cylinder head will tell you what sort of car(s) the engine was originally installed in (Full size, Firebird, A-body, etc) along with the original transmission type and also a little about performance level, but this code is one of the ones that got 'reused' in different model years so in order to interpret it correctly you have to start with the other codes first.

Good luck!

Bear


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## Pontech (Jun 19, 2016)

More photos


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## Pontech (Jun 19, 2016)

Accidentally deleted my last post. I'll try to rewrite a shorten version.

Thanks PontiacJim and Bear, I plan to keep the setup my father built. I'm leaning toward the common 3.73 gear set in the rear. It should only see side roads and the occasional 55mph by pass.

My father and I are close and I grew up seeing and hearing stories about this car. My father and my uncle used to sup up old Pontiacs and Buicks. My father bought this car from my uncle John in 1981. My uncle runs the drag strip and drives wingless sprint cars so I can only assume he was knowledgeable when it came to engine building. My father removed the original 389 and he with a group of enthusiast friends chose to put in a 455. My father is a career machinist so I take his word on what he has told me about what was done to this engine. But I also know he was in his mid 20s when they put this engine together things such as the compression ratio he told me may or may not be true. With that I'll tell you what I know.

This 455 is a 71 model yc block rated for 325hp. The heads are 96s off a 71 400ci. The block is bored .030 over with L2359 030 pistons. The heads have been ported. It has a torker pontiac intake and Carter 4760S 750cfm competiontion carb with a 1 inch riser. It has a Crane fireball camshaft with Rhoads lifters. It has a Mallory electronic ignition with Autolite 85 plugs. My father was told with the radical Cam in stalled and a compression ratio of 11.1 or 11.5 to 1 if would have a hard idle. I don't know how they came up with that ratio. I don't know if more machining was done to the head or block but I will ask him tomorrow.

Today I pulled the plugs and valve covers. I used endoscope to view inside the cylinders. The cylinder walls and pistons are brand spanking new. I used a syringe with a curved spout to apply marvel mystery oil to the cylinder walls and oil the rings. I also coated the valve hardware. I let it set for a few hours and slowly turned the engine by hand one revolution. I removed the air cleaner and examined the Carb internals. It's completely new. A couple hours later I rotated the engine 4 full revolutions. I examined the Muncie M22 and I seems to have a small seal leak. I sat in the car and went throught the gear set. I was only able to find 4 gears in the "H" pattern. What is the gear grid for a 4 speed M22?

After speaking to my father yesterday I found out this engine was never started. It was completely assembled except for setting the rocker arms. They were turning the engine over to start it up and set everything but the battery died and they called it a night and it was never touched again. The valve covers were snuggled down and it was covered and put into a womans garage that my father rented for all these years since 1988 until last week.

Growing up we would often visit the car and pay the rent. I was told it was just sleeping but one day it would be given to me when I was ready haha. This car means a lot to me and I want to do it right. Its a muscle car and thats want to be. I dont want it to be showed up buy these new challengers and mustangs that spoiled kids are driving without ever turning a wrench haha. I want to do it proud and have it respected the way I do. My father and I live 500 miles apart now so it's up to me to put it back on the road in hopes we can go for a ride together.

Again thanks for the help and any reply US greatly appreciated


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## NFDMedic (May 27, 2016)

I wouldn't change a thing, just spruce it up and give it a refresh. You'll always have the memory of him built into that car. His hands were all over it...


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## Pontech (Jun 19, 2016)

NFDMedic you absolutely right


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## Pontech (Jun 19, 2016)

My father told me that this engine was a complete build from ground up. They choose the block and heads. The bottom end was comprised of a kit from PAW (performance automotive warehouse). It was described to produce over 11 to 1 compression. They of course added the blueprint ported heads, intake, carb with riser and ignition.

I wondered if anyone has any copies of a PAW catalog or knows what components would have come with these kits?

Thanks for your help guys!

Josh


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## 1968gto421 (Mar 28, 2014)

NFDMedic said:


> I wouldn't change a thing, just spruce it up and give it a refresh. You'll always have the memory of him built into that car. His hands were all over it...


X2! The car is a tribute to your dad and its also a perfect example of a "day 2" car from that era. You are one fortunate guy!


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## 1968gto421 (Mar 28, 2014)

Pontech said:


> My father told me that this engine was a complete build from ground up. They choose the block and heads. The bottom end was comprised of a kit from PAW (performance automotive warehouse). It was described to produce over 11 to 1 compression. They of course added the blueprint ported heads, intake, carb with riser and ignition.
> 
> I wondered if anyone has any copies of a PAW catalog or knows what components would have come with these kits?
> 
> ...


We recently moved and are surrounded by boxes. When in doubt, do not pitch was my packing philosophy. So when we finally get unpacked, I know I have an old PAW catalog somewhere. If no one else has beat me to it, I'll look up the info for you. Could be several months as I need to build a garage to move my '68 GTO into here. We'll see. I know PAW used a lot of parts from someplace called SS industries....cams, rods bearings cranks in their kits with name brand stuff (like Clevite) being optional.


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## Pontech (Jun 19, 2016)

Thanks guys

Yes! Thanks 68gto421 that would be great! No problem I can wait haha. It's not going anywhere. Thank you for your help.

My wife just informed me that she wants our International Scout II (Henry she named it) complete before I start putting money into the GTO. I excepted he request/challenge haha. This gives me a little time to become more knowledgeable about everything with the car. Like what works what no longer works and what needs to be cleaned up.

Transmission gasket, transfer case rebuild, paint, weather stripping and seat covers and "Henry" will be done though lollol

My wife names all of our vehicles lol


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## NFDMedic (May 27, 2016)

I wish I'd inherit a GTO


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## 1968gto421 (Mar 28, 2014)

I'll keep looking for that PAW catalog as we unpack. Meantime a lot of the members have recommend you study up on the uniqueness of the Pontiac V-8. Remember Pontiac built a basic American OHV pushrod engine, it is not like working on a BRM H16 race engine. But it has some unique things like 30* valve seats and other things.
I would recommend you get Rocky Rotella's two books:

https://www.amazon.com/How-Rebuild-...&qid=1467563659&sr=1-1&keywords=rocky+rotella

https://www.amazon.com/Build-Max-Pe...&qid=1467563747&sr=1-3&keywords=rocky+rotella

These are great books, well illustrated in color and very detailed. Rocky is very meticulous about his Pontiacs and goes into the special characteristics and machinist needs of the Pontiac V-8.

Two books I got from Ames that cover alot on the Pontiac engine are: https://secure.amesperf.com/qilan/D...09B&order_number_e=NDEyNzc2OA==
&web_access=Y

https://secure.amesperf.com/qilan/Detail_Web?part_num=W112&order_number_e=NDEyNzc2OA==
&web_access=Y

Here is a link to a 455 rebuild with lots of photos: Need Recipe for Streetable Budget 455 Build - Page 11 - PY Online Forums

In addition to this great GTO forum, you might want to join the PY (maxperformance) forum for yet more info.

A lot of folks will recommend Jim Hand's book but I never found an affordable used copy (its out of print) so I got one from my library on inter-library loan. It was good but I believe _Pontiac Jim_ gave us access to most of Mr. Hand's info when he provided us with this link where Mr hand re-did all his info for the Dallas Clubs: Building A Strong Street Machine | Dallas Area Pontiac Association

Hope I haven't over whelmed you but this is all the info I know of that will help will with your terrific "inheritance"!


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## Pontech (Jun 19, 2016)

Well not a whole lot has gone on with the car. My wife and I had a son and all my attention has been on him.

But he has recently been coming into the shop with me and I have been washing the old goat and cleaning some parts as well as researching.

I've drained the fliuds and preparing to drop the oil pan. The oil that drained out looked brand new but it had a thick skin that drained out in little clumps. I don't want to clog anything with jelly. 

So I've got a few questions.

1- what's a good way to tell if I have factory rods when th me pan is off?

2- what type of oil pan gasket do you recommend? I've seen 1 piece options

3- what break in oil do you recommend? I was considering Lucas 20-50 high Zink break in. Then running valvoline 20-50 zr1 with zddp

4- what should I do with the grand prix radiator I currently have? Have it tested and use it? Purchase an aluminum replacement? And if so would a 3 core be adequate?

Thanks guys


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## PontiacJim (Dec 29, 2012)

In order to drop the pan, you have to remove the engine. Trying to drop the pan without removing the engine and leaving the trans in place, requires raising the engine as high as it will go until the trans bellhousing hits the firewall floor. You also want to remove the dist. cap so it doesn't strike the firewall and break. You may have to pull the fan so it does not go through the radiator. Even this will only get you enough room to get your hand in, working around the exhaust if its still on, and trying to scrape off old gasket material in this position leaves a lot to desire - and you don't ever want an accident like the engine drops down for some reason with your hand between the pan/block. Got the picture? The engine needs to come out to do it correctly and safely.

Oil pan gasket can be 1-pc or the Felpro replacement. The key is to make sure you use a gasket cement/adhesive on the pan side to keep the gasket in place and from slipping. I have used the Felpro version in the past without problems, but am going to try the 1-pc on my latest build to see how it works.

Factory rods are cast. You will see a "thin" casting line, about 1/16", along the side of the rod. A forged rod has a "thick" casting line, maybe 1/4", where it has been pounded through forging.

I would not use a 20W-50 oil unless you know that your bearing clearances are opened up more than factory. You might go with 15W-40 if you want to go heavier oil. You can use an oil that has the correct amount of zinc in it or use an additive. From what I have read, you don't want too much zinc either. Many cam companies sell a zinc additive when breaking in a new cam. These may be a better choice than going to your local parts store.

Also, if the oil is lump/clumpy, you could have a gooey mess built up in the oil pump pick-up screen and oil pump. You need to check these and you cannot without dropping the pan. I might just install a new oil pump IF I were uncertain as to the PSI of the oil pump on it. You want the 60 PSI pump which the GTO used. Big cars used a 40 PSI pump. There is also an 80PSI pump, but you don't need this for the street and it requires larger bearing clearances. Ask your dad on this one, he might be able to recall what he went with. Mellings is the typical oil pump maker most use.

I would install a new needle/seat in the carb which is made for ethanol gas. It is possible that the original one, if rubber tipped (some were solid brass), will deteriorate with ethanol. Also replace all rubber gas line, at the rear at the tank and front at the engine and use ethanol friendly gas line. If not, it will swell and eventually split and you don't need a fire to burn down your car. Install new gas filters.

As far as radiator, if it fits, why not run it and then decide if you need to replace it. Why spend money you don't need to? I would have it flushed and pressure tested. If it passes, then install it. What is key is a fan shroud.


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## Pontech (Jun 19, 2016)

I'm preparing to pull my engine....but before that I was preping for extraction. I noticed 2 things I was not expecting. #1 the weak cracked plastic shroud holds the radiator in place? Strange.

#2 after removing the Carter AFB 4670 750cfm carb I looked at the relationship between the mounting surfaces of the 1" riser and the carb. It maybe fine. But in my experience you need a good seal over the entire base of the carb for correct galley plumbing, vacuum and overall opperation. Please let me know what you think.

Thanks


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## PontiacJim (Dec 29, 2012)

I don't see a problem. Just want to make sure the gasket seals the outer edges on both carb & adapter, and adapter & manifold. The adapter appears to set inside the Torker top, so I don't see in the pics any flow interference that would disturb airflow from the carb. If there is a step or ridge protruding into the line of sight on the adapter, then you may have airflow disturbance.

The Torker is an open plenum single plane intake. OK for mid-higher RPM's, but you may lose some bottom end responsiveness. You might want to try a 4-hole adapter as the holes will keep air flow velocity up and you may have the best of both worlds. 

No expert on this as I too have run open adapters to mount carbs as we often did when we were young. I would not have known the difference between an open hole adapter or 4-hole adapter anyway - only saw the open hole adapters in my local auto parts stores of the day. So, you might want to play around a little once you get the car up and running and get a feel for it and see if a 4-hole adapter might improve anything.


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## Pontech (Jun 19, 2016)

That's exactly what I was thinking. Thanks for your help.

I would like to pick up a 4 hole adapter. I just don't know if a modern edelbrock adapter will bolt up right with my carb. It's difficult to find concrete info. I've messaged a couple carb websites to see what will fit properly. Not responses yet.


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## Pontech (Jun 19, 2016)

What carberator was the edelbrock torker pontiac (torker 1) designed for?? Holley, What, Carter afb?

Thanks guys


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## Pinion head (Jan 3, 2015)

The original Pontiac Torquer intake was designed for spread bore carb, i.e, the Q-jet. It's name Torquer was a misnomer, as a single plane intake, it killed bottom end torque while providing (with its tall narrow intake runners) limited lower midrange while trying to provide more of a top end charge above 5000 rpm. the Torquer also did not center the carb exactly as did the original Qjet & if ones car was running a shaker hood, there was fitment issues with the shaker top. 

Since the '80's, Pontiac street engine building knowledge has progressed quite a bit. In carefully disassembling this many decade old PAW engine build, it would help to look at things with eyes wide open. Rocky's engine building book is excellent, def worth buying, so is Jim Hand's. In reading the first post in this thread, quite a few things stuck out. First, in order to have anywhere near the static compression ratio that PAW advertised on this build, I would first look & see if there are modified top TRW L2394 dome pistons in the shortblock. Would also be helpful to know if the '71 model 96 casting heads merely had their intake runners gasket matched to RAIV runner height, or if the heads actually had appropriate port work done. 

A pair of slightly milled well ported '71 model 96's on a properly built .030 or .040 455 shortblock can make some really good power, Jim Hand's brother Floyd with his '66 LeMans is one out of the "Dallas bunch" that built quite a few very strong such 462-469 cube "96" head builds. Their well scienced out builds, with no limiting factors like a Torquer intakes, & heavy '70's forged domed pistons which require larger cyl wall clearance, work very very well. Mid to high 400hp, well over 500 ft lbs of torque, depending on extent of portwork, with a really strong mid range & good topend.


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## PontiacJim (Dec 29, 2012)

Pontech said:


> What carberator was the edelbrock torker pontiac (torker 1) designed for?? Holley, What, Carter afb?
> 
> Thanks guys


Quadrajet. The Q-jet has small primaries and large secondaries, unlike the AFB you have or a typical Holley carb. However, Holley makes a spreadbore. (I tried an 800CFM mechanical secondaries on a built up Chevy engine with an adapter to make it fit the squarebore intake. It was OK, but not impressive and I wound up taking it off). There is also the Mopar Thermoquad which came in 800 & 850 CFM's and there was a competition series racing one at 1,000 CFM's that could be used on Pontiac intakes if you had the engine/horsepower that could use that size.

The Torker is more of an upper mid-range/top end intake that is superior to all stock manifolds above 5,000 RPM's. The design was unique at the time having a 2-step plenum that Edelbrock called a "Volu-Step." Front runners are tall and narrow while the the rear runners were made lower and wider. That lower forward shelf in the front of the plenum was designed to avoid the fuel mixture from slamming into the manifold floor caused by the high velocity/flow of the small primaries used by the Q-jet. You will lose lower/mid-range power/torque being a single plane manifold and it may not have any advantage for an engine running under 6,000 RPM's. 

The factory dual plane intake is still the best bang for your buck if running under 6,000 RPM's. The RA IV aluminum is another good choice, but it has taller runners where it mates to the head and you either need the correct heads or can gasket match any non-RA IV head so the two surfaces mate together evenly and don't create turbulence at the mating surfaces due to the mismatch. I don't know if the Torker intake runners are of the stock size or RA IV size (but assume stock sized). Often they are cast to fit the stock type heads and have enough material to be ported to match the RA IV heads.

I can't speak of any of the other intakes out on the market as I have never used them. The only other aluminum I recently used was an older Offenhouser 360, split single-plane, (just because I was given it) on my last 400 build that was designed for a squarebore and I used an adapter and slapped a Q-jet on it. Ran it 7 years without problem and it pulled good. Car was a 3-speed manual.

Seeing the Torker is period correct for the car, I would keep it at this time and source a Q-jet to put on top (no carb adapter) and see how it goes. Your engine is probably built better to take advantage of the intake and it may work well. I had one on a Pontiac 400/4-speed once for a real short time and I noticed the loss of lower/mid range, but it kicked in higher up. My engine was basically stock, so it hurt performance as a street car and I put the factory cast iron intake back on and picked up all the lost power.

Just my 2-cents on it. :thumbsup:


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## Pontech (Jun 19, 2016)

Hey guys I'm try going through the engine now but I'm having a hard time breaking the intake manifold loose from the heads and timing cover.

Any idea how to get this intake to pop free??

Thanks


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## BearGFR (Aug 25, 2008)

Pontech said:


> Hey guys I'm try going through the engine now but I'm having a hard time breaking the intake manifold loose from the heads and timing cover.
> 
> Any idea how to get this intake to pop free??
> 
> Thanks


Did you remove all the bolts, including the small one on the front that goes through the tab on the front of the timing cover, and also the one on drivers side rear that goes through the throttle cable bracket?

If you're sure you got them all, then use a long pry bar - rest it on top of the timing cover and pry up underneath the water crossover on the intake.

Bear


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## Pontech (Jun 19, 2016)

I tried it once more where you mention Bear and I popped right up haha.

Thanks for the help!

Looks like something had a nest under there at some point lol. Engine is coming out and those heads are getting cleaned.

Here are some pictures


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