i have a 305 tbi and i was wondering if i can swap a cam out of a 350 into it. and will it do anything or is it not worth it?

yeah the cam will fit, make sure it's a roller if you have a roller set up, or a flat cam if not a roller. without knowing what the cam is you want to install it's be hard to say if you'd see any gains

All TBI's are roller so you should try and obtain a roller. A flat tappet cam will fit, just as long as you use the flat tappet lifters.

it would be a stock cam out of a 5 speed camaro or firebird

TPI car?

ummmmmmm did you just use stock and 5 speed in the same sentence? That means you're talking about a 305... LG4 or L69, and not TPI, Carbeurated. If you want a cam out of a 350, it's going to be auto.

Unfortunately they quit offering the best engine with a manual transmission in 81

the car im looking at getting the cam from is a ?88? i think with a 350an five speed . it must be an aftermarket mod.

Yup. Unless it's actually a 305.