I have a 68'400 that came with my 68' firebird project.I'm putting a 455 in the 68' and i would like to put the 400 in my 83' firebird.could someone tell me what I have to do to get it in my car? THANKS

 

You'll spend alot more $$, and have to fabricate parts trying to put a Pontiac 400 in it. A Chevy 400 is much more of a bolt-in.

Try a few searches, it's been done by a few and you'll need to decide whether it's really worth it or not.

 

There is little to no fabrication involved...see the 455 thread above. Get the mounts and headers from Chief Many Horses (some have used stock Pontiac mounts and manifolds), get a BOP Th350 or Th400 (or use an adapter plate with a Chevy trans), and an aftermarket trans crossmember/torque arm (or use a kit from B&M or Hurst). Easy. Parts for the 400 aren't that much more than SBC Chevy stuff, either, and if you already have the motor you might as well use it. Its not like Chevy 400s are exactly growing on trees, either...

 

Not taking anything away from LT1guy, but I'm 99% certain those headers, adapter plates etc. will be just a bit pricey. If I were going through the particulars of sticking a BOP engine in a thirdgen. it'd be a 455 like he's doing.

If the cost and parts were just as cheap and readily available, you'd see alot more BOP combos on this board. At least around here, your odds of finding a Poncho 400 or 455 is just as good as finding a Chevy 400.

Heck, at one point I was thinking of putting a Caddie 500 in mine...and yes, that can be done too!

 

Doesn't really matter if it's a 400 or a 455 Pontiac, the blocks are identical, the headers are the same, and finding a BOP tranny is easy to find. Plus you're putting a true Pontiac motor in a Pontiac car (which should have always been done, but that's another argument)

400-455 Pontiac = mega torque (if it's like a 68-71 model)

The 400 in my GTO was 360hp 420lb torque at the flywheel which is a whole lot more than you would ever get out of a stock bowtie engine of the same CID.

 

Stock...I agree. Non-stock is another thing. See sig.

Yeah, I wish they never droped the BOP engines either. Heck, the TTA is the best Pontiac Buick ever built!! Oh no....here come the TTA owners....

 

I think the reason you don't see more BOP swaps is that people think they are difficult or too expensive, and people in this forum like to talk people out of doing them. I mean, this is the "engine swap" forum, and swapping a 350 or 400 Chevy in place of a 305 isn't IMHO an engine swap.

The headers (full length) are $529.95, the mounts are $89.95. I'm building my own headers, and possibly the mounts too (the IA ones look kind of flimsy). In GA, Chevy 400s are tough to find, and if you do find one for sale (those that have them usually don't want to part with them), they're expensive. Pontiac 455s and 400s are both available and cheap (paid $50 for my shortblock), and the performance parts, while more expensive than SBC, still aren't that expensive compared to other engines. There are good factory heads that respond well to porting, so you don't necessarily have to go aftermarket. Most places will practically give you a BOP trans (my TH400 was $50), or you can pay about $75 for an adapter for your Chevy trans.