1977 Pontiac Trans Am Questions About Engine

[BlackSS2005]

My friend bought a 77 Trans Am with 50000 original miles on it. It's been sitting for a while and he's doing a frame off restoration. We have looked at the build sheet from under the back seat and decifered somethings about it. The label on the shaker hood says 6.6 litre. I've read a few things on here saying it might be a 403, but I also read that there was no 403 in 1977. The build sheet says it's a 400 but just wanna make sure. He's also looking for advise on building the engine after we figure this out. He wants to buy a engine kit for the rebuild but not a stock one. He wants a mild cam and we aren't sure so I guess thats why we are on here asking.

[MrPbody]

The most prolific engine in '77 WAS 403. Generally speaking, if the scoop doesn't say "T/A 6.6", it's a 403. There MAY be variations, but I've never seen one.

Without going into great detail, if the oil filler is a pipe coming up from the front, it's an Olds. If the oil filler is a cap in the valve cover, it's a 400 Pontiac.

"Kits" for either will be difficult to get, and be "right". There always seems to be SOMETHING out of character for most non-Chevy "kits". Engine parts, however, are readily available. The Pontiac will be a bit less money for the "good" parts than the Olds. The reason is the same reason small block Chevy parts are cheaper than most... VOLUME. LOTS of 400 Pontiacs being built today. Not near as many Olds of any description.

Let us know which engine it is for sure, and we can start pointing you where you need to go. Either is "good" for making streetable power and torque. If he wants REAL power, the Olds will break his budget. The Pontiac will only fracture it...(:-

Jim

[BlackSS2005]

Originally Posted by MrPbody

The most prolific engine in '77 WAS 403. Generally speaking, if the scoop doesn't say "T/A 6.6", it's a 403. There MAY be variations, but I've never seen one.

Without going into great detail, if the oil filler is a pipe coming up from the front, it's an Olds. If the oil filler is a cap in the valve cover, it's a 400 Pontiac.

"Kits" for either will be difficult to get, and be "right". There always seems to be SOMETHING out of character for most non-Chevy "kits". Engine parts, however, are readily available. The Pontiac will be a bit less money for the "good" parts than the Olds. The reason is the same reason small block Chevy parts are cheaper than most... VOLUME. LOTS of 400 Pontiacs being built today. Not near as many Olds of any description.

Let us know which engine it is for sure, and we can start pointing you where you need to go. Either is "good" for making streetable power and torque. If he wants REAL power, the Olds will break his budget. The Pontiac will only fracture it...(:-

Jim

Ok he's got the Pontiac 400 cuz the oil filler cap is on the valve cover. He wants to make good streetable power but he doesn't want to dump a pile of money into it. He'd rather just change the cam if it would make much difference. But we were told by someone that a mild cam won't help much because of the low compression ratio(around 8:1 I guess). Let me know what the best options are for him. Thanks

[MrPbody]

Okay. It's the ol' Injun! Good. First step? Buy Jim Hand's book "How to Build Max-performance Pontiac V8s" by SA Designs.

Figure out what casting numbers the heads are (the info on how is in the book). Then, we pick a cam suited.

Lots of choices here, and not too much budget required. 400-plus HP is easy enough to get.

Jim

[79Bandit]

Originally Posted by MrPbody

Okay. It's the ol' Injun! Good. First step? Buy Jim Hand's book "How to Build Max-performance Pontiac V8s" by SA Designs.

Figure out what casting numbers the heads are (the info on how is in the book). Then, we pick a cam suited.

Lots of choices here, and not too much budget required. 400-plus HP is easy enough to get.

Jim

that book helps a lot! trust me. and the book also has engine recipes in the back well worth the money

[smithg15]

Hi Guys,

Just found this forum while browsing and have the same question. I have the Pontiac 400 (Texas car) with the 6X heads. Not sure on the 6X-4 or the 6X-8 but will know in a few days when I get to the car and have another look.

I have imported a 77 Transam SE to Australia in 1992 and have had it in storage since. I have done a conversion on the car to RHD with the firewall, brakes and steering all swapped over.

Not happy with just leaving the car stock standard I am about to strip her down and re-do the lot but my main concern in the engine.

What would need to be upgraded to get the 400 HP as mentioned above??? I would have to grab all the required parts on my next trip to CA which might be early in the new year.

Any help would be greatly appreciated with suggested parts and estimated costs to get the motor rebuilt and around the 400 HP mark. Maybe a good suspension parts store will be handy aswell in CA. Probably going to grab springs, sway bars and all the rubbers needed.

Note I have built several motors and will do most of the work myself.
Obviuosly all machining will be done at the shop, but I will disassemble / assemble the engine myself.

Thanks for your help.

[MagicRat]

You may have better luck getting an answer if you start a new thread for your question, rather than resurrecting someone else's old thread.

To answer your question, the 6X heads were okay, but were very low compression. There are several aftermarket Pontiac heads that benefit from newer technology and are available in aluminum for less weight. It may be easier and more productive to use a set instead of reworking an ancient (and possibly cracked/warped) old heads.

The rest of the task is simply using the correct intake manifold, carb, headers and cam.

IMO if you enjoy a challange, you can port the heads, mix and match parts with lots of trial and error. That may be okay for someone in the US where lots of parts are available.

But if everything has to be shipped to you, save yourself headaches and get a matched set of aftermarket heads, intake, carb, headers and cam from a company like Edelbrock, who have (hopefully) engineered the parts to work together.

Finally, those Pontiacs had relatively weak, cast connecting rods. If you are serious about power, consider a set of aftermarket forged rods, for greater reliability.