# 1968/69 Pontiac 400 question



## BradleyL (Sep 5, 2017)

I have a nice running Pontiac 400. It was in a '79 Silver Anniversary Trans Am when I bought the car, and I was told it came from a '68 or '69 GTO. The block casting # is 9790071. The date code is L218. The front of the motor has 0388560 (Vin for car, correct?), and YS under it. That is for a 350hp 400 with auto. Heads have 62 and date code of L216 and the other is a few days off, I think L218. My two questions are:

I am looking to just build a decent street motor to replace the 350 in my '68 Firebird. Is this motor worth more than any other 400 to someone looking to restore a car than it is to me just as a basic 400 that I can get out of any other later TA? I would be going with alum. heads, different cam, etc. Should I try to sell it to someone looking to go the resto route, or just build it as I would any other 400? If sell, any idea of value? It is complete motor, oil pan to intake and exhaust manifolds. I am not looking to get max $ out of this motor, that's not what it's about. I just don't want to build this motor and someone say "you could have built any Pontiac 400, why would you build a motor that some resto guys would have killed for", or something like that. 

Also, have a friend looking for a 400 exhaust manifolds for his '77 TA. Are the exhaust manifolds that came originally on the YS motor worth anything or just like any other exhaust manifolds, which is pretty much squat?

I tried to find my own value for the motor, but couldn't find much of anything other than one block that sold on ebay years ago...

Thanks in advance.


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## bigD (Jul 21, 2016)

"...Is this motor worth more than any other 400 to someone looking to restore a car..."


Yes, it should be worth some $$$$ to anyone who wants to build a numbers correct '69 GTO with auto trans.
I'd sell it.


"...I am looking to just build a decent street motor to replace the 350 in my '68 Firebird..."

I'd try to find a 481988 or XX 481988 block to build.

"...I would be going with alum. heads, different cam, etc..."

Here's an alum head 400 crate engine, with block included, just for an example. This guy has a good rep, but I've never bought from him. 

http://lenwilliamsautomachine.com/400_Edelbrock_Heads.html

Obviously, you can start with a block & build from scratch, if you prefer. Butler sells ready to assemble short block kits, if there is not a good Pontiac shop in your area. Butler also has a good rep, but I've never bought from them either.

https://butlerperformance.com/c-123...-kits-short-block-kits-ready-to-assemble.html

The early block only has 2 motor mount bolt holes on each side. The '79 Bird used mount brackets that used the later 3-hole pattern. So, I'm just curious to know exactly what type mounts are in the Bird. Does it have the motor mount adapters ? Or maybe some homemade set-up ?

https://butlerperformance.com/i-244...-455-set-bpi-f10774.html?ref=category:1393551


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## BearGFR (Aug 25, 2008)

That's a model year 1969 400 out of an auto transmission GTO. Very good, very strong block - and a perfect platform for building a 461 stroker. That's exactly what I did with mine, and it's the numbers-matching engine the car was born with.

Bear


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## Shake-N-Bake (Jun 16, 2015)

I would build the 69 block that you have already unless you are able to find the owner of the specific car that engine belongs to. Otherwise it's about the same value of another like 400 block IMO...

I have a 1967 Firebird 400 WZ engine that had been rebuilt but never run. Will take it all apart soon since its been sitting for a while. I posted the EUN on the Firebird forum in case someone out there has the original car. If nobody responds by the time I have a need for that engine then I will just use it myself. 

Sent from my XT1585 using Tapatalk


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## BradleyL (Sep 5, 2017)

Thanks everyone. Any idea of a value? $1500 CDN seem reasonable for a complete motor from intake down with manifolds or is that a little high?

I sold the '79 Silver Anniversary to a buddy but also included the original 403/auto with the car and he is putting those back in it and I ended up with the 400 back. I just took a look and there are some crudely made motor mount adapters still on the block and they are only using the two holes on the side and not the top holes.


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## bigD (Jul 21, 2016)

"...Any idea of a value? $1500 CDN seem reasonable for a complete motor from intake down with manifolds or is that a little high?"


You never know what you can get til you advertise it. I'd put it on all the Pontiac Facebook pages, and the PY forum. Might also put it on Ebay. I'd ask $2000 & see what kind of offers I could get. 


" I have a nice running Pontiac 400..."

If you can't get $1500 as is, and it runs decent, I'd put it in the Bird. An engine is easier to sell if the buyer can see & hear it run. Hey, you might like it, as is. And $1500 won't even buy the alum heads you want. Unless you have most of the parts & can do all the work yourself, a correctly built alum head 400 will cost well over $6k. 

https://www.facebook.com/groups/448312378514583/

https://www.facebook.com/groups/pontiacsonline/

https://www.facebook.com/groups/pontiacdragracers/

https://www.facebook.com/groups/1470033089992751/

http://forums.maxperformanceinc.com/forums/forumdisplay.php?f=446


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## BradleyL (Sep 5, 2017)

Thanks again bigD. I have an engine test stand with gauges, rad, fan etc., so a buyer could hear it run. I have also worked on a ton of engines and took a high performance engine building course at night school at a college. I was going to stick the 400 in the car, sell the 350, and just upgrade the 400 as I went along, but am considering selling the 400, 350, and some other stuff I have collected and just buy a decent crate motor from Butler or someone else. We are just about to sell our house and move to our cottage, so I won't have a garage/shop or the time for a year or possibly two, and that's why I am considering just selling the two and buying a crate motor. It's one less thing to have to find storage for until I get a new shop built. I will be busy finding another lot, building another house, building another shop, etc. The car unfortunately is going to have to go on the back burner for a bit.


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## Hjudge49 (Feb 25, 2015)

I recently had a 400 rebuilt. With the cost of a set of Edelbrock aluminum heads, Edelbrock manifold, Doug's headers, holly double pumper, a custom cam and a total bottom end rebuild (crank, pistons, rods, blueprint and balance) I have about $8000 in the engine. Now it puts out 445 hp on the Dino, but it ain't cheap.


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## Sam68 (Apr 28, 2019)

Hi I have a 68 lemans with a 350 stock which I am rebuilding I am using a Stroker kit from butler Performance and the #16 hp heads with big valves I am thinking about going .30 over with the bore with a ram air intake and a ram air 4 camshaft but wanted to know if any up to date camshaft that may be a good fit I am looking for good power with a nice classic idle also looking to to change my rear end gears they are stock now but not sure what would be a good gear set for a street car but not totally Choke my power any advice would help a lot


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## bigD (Jul 21, 2016)

Those 041 cams are pretty nasty in street engines with less than 428 cubes. If you insist on using one, make sure you also run Rhoads lifters. 

What will be your final cubic inch & compression ratio ?

Compression Ratio Calculator - Wallace Racing

What trans do you have ? If auto, what stall ?

Cubes, CR, Cam, trans, converter, rear end gear, and how you'll be using your car are some of the things that are involved in choosing the correct combo. There are good combos, OK combos, and bad combos

Let's just take one possible combo for an example. 383 cubes, 9:1 CR, TH400 trans, 10" converter with at least 2600 rpm flash stall, 3.23 gears. For this combo, a Summit 2801 cam might be a decent cam choice, on the low end, and the Summit 2802 might be a decent cam on the high end, for a healthier sounding idle. 

Between those 2 might be a Lunati 10510312. 

http://www.lunatipower.com/Product.aspx?id=1759&gid=278

Above the 2802 might be the Crane 283951.

https://www.summitracing.com/parts/...EixRF9nyONKDNg0eySh9VIuf6FmIYCaIaAusEEALw_wcB

Then there's the high priced Crower 60243.

https://www.summitracing.com/parts/cro-60243

I think the Howards 410051-14 is the biggest cam I'd even consider, and then ONLY with Rhoads lifters. 

https://www.summitracing.com/parts/hrs-410051-14/overview/make/pontiac

In fact, with only 383 cubes, I'd even want Rhoads lifters with the 2802 cam. The 2802/Rhoads might not be a bad combo at all. 

The Voodoo 262 cam might also be a good cam for a 383. 

http://www.lunatipower.com/Product.aspx?id=1775

If you go with this cam, engine builder Paul Carter recommends more spring pressure(about 125# installed & at least 300# open, if I remember correctly) than is needed for many regular type cams. The Voodoo cams have a steep ramp.

For a mild street 383, the Summit 2801 might be hard to beat, for all around performance & lowest price. 

https://www.summitracing.com/parts/sum-2801

An 068 clone is similar, but has less lift(just over .400), & costs more. 

https://www.autozone.com/internal-engine/camshaft/melling-camshaft/107135_705947_0


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## Sam68 (Apr 28, 2019)

This is the kit from butler I am using


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## bigD (Jul 21, 2016)

That 4.25 stroke assembly will make in the neighborhood of 400 cubes. 

Here are a few mid-range cams. 

Summit 2801

Lunati 10510312

Summit 2802

Crane 283951

Voodoo 262

Below those would be an 068 clone, such as a Melling SPC-7. 

Above those would be the Crower 60243, then the Howards 410051-14, then the 041 clones such as the Melling SPC-8. 

As a general rule, the smaller cams will provide more low rpm vac & torque, and a smoother idle. The larger cams will produce more power above 5000 rpm, but a rougher idle, plus less vac & low rpm torque.


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## PontiacJim (Dec 29, 2012)

Depending on cam lift, duration, and even overlap, make sure the 2.11" valves have good clearance between the cylinder wall to valve so it is not "shrouded." The 1969 350 HO engines used the larger 2.11" intakes and had a factory scallop/notch on the top of the bore to match the valves.

I have enclosed a photo of a 350CI block with the scallops at the top of the bore. You can see there is one for the intake valve and one for the exhaust valve. This is a late cast 1969 block used in a 1970 year car. From what I have read, not all years after 1969 had these factory scallops. So depending on cam, keep this in mind.

I pulled this article off the internet which is a build for a 350CI:

- "All 350s can safely be bored 0.060-over. The most desirable blocks to look for were made from 1968 through early 1970. They may not have the correct mounting bosses needed for some later applications, but their larger cylinder-bore valve chamfers require less notching for valve clearance with big cams. Check for valve-to-bore contact by placing the valves, retained by clothespins, in the heads. Coat the potential bore-to-valve interference areas with machinist’s dye, place the head (with no gasket) on a bare block, and carefully drop the valves to establish the contact point.

Valve To Bore Contact Is Most Likely To Occur On The Exhaust Side. Grind Clearance As Needed. Maintain 0.025 Inch Clearance Between The Bottom Of The Notch And The Top Of The Piston Ring Land At Top Dead Center."

Here is where I got this info - https://www.hotrod.com/articles/672hp-pontiac-350s/


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