455 Super Duty rebuild guidelines

[tom406]

Hey, a shop I'm friendly with is rebuilding the engine of an original '74 SD455/4sp Trans Am. Their builder is sharp but is more experienced in Ford/Chev builds. I remember a thread with good tips (don't add a lot of compression, etc). Can someone point me that thread or a good article on rebuilding SD's properly? Thanks!

[KenMaisano]

http://www.yenko.net/forum/showthread.php?t=141932&highlight=maisano

[KenMaisano]

A good stock rebuild is all they need. Compression doesn't really do much on these large stroke motors. Summit 2802 is a great replacement camshaft for the OEM 744.

[tom406]

Thanks Ken

[tjs44]

Ken was wanting to keep more toward stock.If mine and wanted more HP I would kick it up to 9 or 9.5 CR and put a cam in more in the 230-236 range with more lift.Those heads will breathe,the factory had to back everything off to meet smog.They got caught in a VW type smog cheat and had to reduce the cam in the SDs.FWIW,Tom

[KenMaisano]

Ken was wanting to keep more toward stock.If mine and wanted more HP I would kick it up to 9 or 9.5 CR and put a cam in more in the 230-236 range with more lift.Those heads will breathe,the factory had to back everything off to meet smog.They got caught in a VW type smog cheat and had to reduce the cam in the SDs.FWIW,Tom

Yes I agree if your looking for more of a hot rod. This is my 70 RamIII auto trans and 323 gears . with a Crane HR230 230 238 528 540 ran killer!!
https://www.facebook.com/144748208954595/videos/561553117274100/

[njsteve]

http://i1087.photobucket.com/albums/j467/njsteve-engines/th_grammacar.mp4 (http://i1087.photobucket.com/albums/j467/njsteve-engines/grammacar.mp4)

Another vote for that Summit 2802 cam (but remember you have to change the distributor gear on any cam swap on an SD455 since no one makes the correct camshaft that I know of, with the right gear size)

[tom406]

Perfect-the exact 3 guys I wanted to jump in-did! Thank you for the input.

[tjs44]

FYI,there is a NOS GM SD cam on ebay,has been on for awhile,stupid money.Tom

[tjs44]

here ya go
http://www.ebay.com/itm/NOS-1973-1974-455-Super-Duty-camshaft-Pontiac-Trans-Am-Formula-/122011268731?hash=item1c6870367b:g:hgUAAOSwNNxWFE0 U&vxp=mtr

[njsteve]

I think all the internal parts for my Gramma Car 455 build cost less than what he wants for that camshaft!

[tjs44]

I said it was stupid money BUT it is the only NOS one I have seen forsale in the last 20 years.Im sure there has been others but not on ebay or the pontiac boards I watch.Tom

[Tracker1]

If it were my SD-455, it would be with a known/trusted Pontiac builder. That is an expensive, exotic mill to be doing a "Google" rebuild on.

[njsteve]

Agree. There are a lot of weird little idiosynchracies with Pontiac engines that most builders don't know. Like the internal rear oil galley plug by the distributor brace, inside the block. If you leave it out, the engine shows oil pressure on a gauge, but is only getting oil to half the engine and death soon results.

[tom406]

I agree with the reasoning, but it's not my project or my shop-I'm just sticking my nose in a bit to help ensure a better outcome. The owner of this particular car isn't likely to send it off to someone he doesn't already know/trust.