well it depends, Is it a t bird 292 ? It could have a holley 94 or a wider base 2bbl or a 4 bbl. Just depends. What is the motor from? what year? Do you have a picture?
it's not a tbird motor. and it has a 4 barrel manifold he is gonna buy an edelbrock carb. my question is what cfm?
you need to see if you have a 1957 and after dizzy too, otherwise you're wasting your time. Probably the 500 would be adequate.
A stock 292/312 would run the best with a carb not over 500cfm. They will run good with a 600, but its a bit too much.