I have a manifold from my old 1979 Trans-am its a pontiac performer with carburetor, and i was wondering if it would be able to fit the chevy engine.

its came off a pontiac 403
and im wanting to put it in a chevy 305

 

The answer is no....
First of all the 403 (which I also have in my 79 T/A), is an Oldsmobile small block that even Olds doesn't "recognize" as one of their own.

The Olds engine has a wider intake valley....(the heads are farther apart). Chevy blocks are much narrower.

Be careful on selecting an aftermarket manifold for the 305....the ports are much smaller than the 350....good luck!

 

so would a 350 carb work on the 305?

 

So what specifically is a "350 Carb"?????
What year is the 305???
Was it originally fuel injected???
If so, the fuel pressure is much too high for a carb.....a pressure regulator will have to be used.
If the carb is a 350 CFM unit....I'm guessing it's a 2 bbl....
Need more info please!