Would a performance chip do any good on a stock 92 firebird 305, or would i just be wasting my money?
IMO, It might help a little, but nothing huge. Save your money for engine and exhaust mods.
I would do a combo, a chip and mods. If you just add the chip you may or may not see any gains, gamble on your money. Intake and exhaust helps the engine breath but you risk leaning the motor out due to the efi system. Just remember that the chip has been tested on a test engine and the results do vary. These chips are burnt and cannot be adjusted or modified. If your really serious you can get a 70 dollar aldl cable (and maybe a wide band o2) and pull some data logs, there are people on forums that can built you a custom chip to work with your motor (using the data) with guaranteed results.
Search Pontiac Firebird Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Pontiac Firebird Experts