Im just wandering if i can put exhaust minifolds from an 1985 pontiac trans am 305cu in (5000 cc)
On my 82 Firebird without making any major adjutments?
I also currently have a 305 5LTR V8 but want to know if they will fit and also would there be any difference in making the change

 

Depends on witch engine the exhaust manifolds came from.
the T.P.I. motors (both 305[5.0] and 350[5.7])and the
L-69 H.O. motors have the same exact manifolds, same part # even.

The T.B.I. and low out-put carb'd 305's have the same manifolds.

I'm not sure about the carb'd 350's, but i think that they are
the same as the T.P.I.'s.

If the manifolds are different you would have to change the "Y"
pipe, or have a custom one made.

Contrary to popular belief, there is NO performance difference
to the IROC/T.P.I. manifolds, they are the same size internally.
The only advantage is that it is easier to use 2.5'' exhaust tubing
with them.

 

There's no carbed 350's available in 3rd gens. So if you use 350 manifolds from another vehicle, i'm not sure if it'd end in the same spot, such that you can reuse your Y pipe. But I think that's just rehashing the same thing Atomic said.

the new manifolds should bolt right in, but won't change a thing. Won't be worth lifting up the wrenches to put them in. Unless your current manifolds are cracked or something, and the leaks are making you nausious as your drive.
Wait until you can afford some headers


I like your car, looks like 2nd gen 15x7 snow flakes? Mine is quite similar:
https://webdisk.ucalgary.ca/~jmknopp...t,%20may06.jpg

 

Sweet car sonic is it the 82 Recaro trim Trans am ?

Yeah i have the second gen snowflakes on i like them so much i thought id have them on an 82.


Also im not looking for parts for the 350 ive still got the 305 5 ltr engine in at the moment.

 

Nah, it's just a normal trans-am. PMD seats though. It's a fun car.

350 manifolds fit fine on a 305, that was the point. They're usually a bit bigger, and might flow better, but my point was that if they are bigger, they won't change it enough to be worthwhile.

Hey, is your reverse gear top left or bottom left? 4 speed manual right?

 

Reverse on my car is top left and yeah its 4 speed manual. id like a 5 speed really as it tops out at 130 :-(
Not too bad i suppose for the age of the car but i guess top end speed wasent pontiacs main priority and i would only use it at those speeds on a track *cough*
I also have the pmd seats too, Ive just poted some pics on vBgarage if you wanna take a peek.

 

reverse in top left = Borg Warner T10 transmission - you lucky dog you. Stronger, better ratio's, etc. The more common one is in bottom left, that's the crappy saginaw.

 

To repeat what the guys have said, the larger manifolds wouldn't be worth the time/effort/money, but if you have access to the larger manifolds along with their larger Y', a high-flow cat, and larger intermediate pipe, you'd see a difference. Check the Y difference, for example, in the following link:

https://www.thirdgen.org/forums/exha...-question.html

JamesC

 

Thankyou all for your help ive decided to get some Hooker competition headers and am just waiting for them to arrive