BBC issues

I'm putting a BBC in my 1981 trans am it came with a 301 but wanted something bigger I'm going to have clearance issues so what headers should I get I have headman long tube headers on my 301and it's tight. Thanks!  

Maybe shorty headers designed for a big block Camaro, I can't offer a specific make or part number because I've never put headers on this combo. When I bought my 79 Formula, it had a 454BBC in place of the original 301, I yanked that turd out in a hurry and put it back to real Pontiac power before any of my friends saw it!
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

Ya you would be better off putting a real Pontiac engine back in it and you would get a lot more help on this site with that swap.
Real Pontiac power just gets more respect then a chevy in a Pontiac any day with real Pontiac fans.
(I yanked that turd out in a hurry and put it back to real Pontiac power before any of my friends saw it) MAN NOW THAT IS FUNNY!  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

In all respect I'm a true Pontiac fan as all the rest but money is an issue and as long as it's GM I'm happy no foriegn junk.  

I don't really appreciate not being called a real Pontiac fan when chevy and Pontiac has been working together for years where do you think the 350 came from  

Dude, nobody means any offense, but this really is a Pontiac forum for a reason. We have all spent years running rings around Chevys. The Chevy 350 and the Pontiac 350 are two completely different animals. The first is an oil spewing joke that was made specifically for economy, the parts are cheap for a reason. They run high RPMs's and that is their claim to fame. By the time it winds up to 6 grand, the guy in the Pontiac 350 is having dinner.  

Besides, by the time you buy all the parts to make a BBC fit and function correctly and build it for performance, you could have had a real Pontiac that will bolt right in place of the 301 with very little work. Most stock BBC`s are pretty weak and need just as much work to make power as an older Pontiac and the parts aren`t any cheaper either.
Sorry if we come off as Pontiac snobs, but the fact is most posts on here deal with true Pontiac powered rides. The late model/corporate power guys don't seem to bother with us, I assume they get their info off other forums dedicated to EFI mods.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

The good 350 came from Pontiac.
Barney is right bbc cost as much to build as a Pontiac Engine.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

I mean I could only afford a 454 since 455 are expensive and difficult to find I'm doing a performance build up on the 454 with afr heads Harlem sharp rockers speed pro pistons I'm doing a high power build up. I might sell the engine when I get it all done I'm going to try to sell it for profit and buy a 455 but if I can't get what I want for it then I'll have to use the 454 which you all have to admitt makes serious power  

If that's the case, and don't get me wrong I'm not being snotty, you might try a forum from a Chevy mag like Super Chevy and address your questions as if you had a Camaro. Aside from the exterior body panels and a few underhood details the two cars are virtually identical. Those guys will be much better at answering your BBC related questions. When you need advice about the Pontiac specific parts of your car, feel free to drop us a note.
On the topic of the BBC swap, remember there are lots of changes to make. The frame mounts need to be moved and the block brackets are different as well as all the accesory brackets (alt/PS/AC), the battery, starter and alt are on the opposite side so wiring needs to be rerouted. Ditto the fuel pump and lines. The 301's TH350 trans may work if it has a dual bellhousing pattern, otherwise you will want to upgrade to a TH400 to handle the extra power, that also requires a shorter driveshaft with a larger slip yoke. You may also find you need heavier front springs depending on how sagged out the old ones are.
In the end, build your ride to suit yourself and enjoy it. However if you show up to an all Pontiac show, don't be surprised if they turn you away (I know, it's not fair), the people who run those shows can make us look as if we welcomed your BBC/TA with open arms.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

I got a Pontiac 455HO long block from HiLo. Your 1981 Trans Am will be greatly offended by having a Cheavey heart transplant. It will probably not even start without a pacemaker.  

If you can't find a 455 all is not lost- go get a 70-75 no.481988 400 block and stroke it to 462 w/ a 4.25/6.8/3.0 stroker kit. Kits w/ cast cranks start at $1400 and go to $2000 w/ forged cranks- all of the well-known Pontiac shops have them and they are proven.

The 455 is still very popular, but the 400 stroker will be stronger than the 455 (more metal in the 400 block) and will rev harder thanks to the 3.00" mains and 2.2" BBC rod journals. You'll spend about the same money building it as a 455, and with ported iron heads you should be able to get 450-480 hp.

Geno