ok so i just got an 84 camaro it has a 305 in it the guy i got it from said it had a holley 650 wich turned out to be a 600 because i took it to a local perfromance shop and they took some number off the front and said its a 600 but when i get on it real hard it will hesatate or back fire or both i had a friend adjust the carb and he said it may need to be rebuilt or the timing may be off????? any advice helps

 

Rebuild the carburetor, then check your timing. Maybe even give it a tune up, (plugs, wires, cap & rotor), if it looks like it hasn't been done in a while. And a 600 is plenty for a 305.