[Ziegelsteinfaust]

A 500 cfm 4 barrel works great on a 283, and a 650 Vacuum secondary is not so bad either.

A 2 barrel has a tendency to run richer throughout the rpm band due to the 2 vs 4 barrels. I put a 500 cfm holley 2 barrel on a 289 I had to mess with people, and it didnt lay down more power that I could feel when I went to a 4 barrel. My mpg did go up a couple mpg on the highway due to better control of part throttle air fuel ratio.

Running large holley or edelbrock carbs on smaller motors. Such as a 800 cfm on a 350 or a 750 on a 283. Q-jets are different here due to the small primaries. But you have issues with progressive afr, and part throttle tip in feels softer. Correspondly if your constant turning 5000+++ rpm they work better since the engine can not pull more fuel then it needs allowing control of the afr. So if this was 1969, and your running a trans am race this gives you extra mpg. So you have to fuel less often.