At Beech Ridge Speedway up here in Maine, we had to run the rochester 2bbl carbs for years. 2bbl cast iron intake, no porting to heads or intake. We also had to run a .450 max lift cam 11:1 max compression and flat top 2 valve relief pistons. 1.94 intakes and 1.5 exhaust. 1/3 mile track, turned 6 grand at the end of the straight with a 1-3/8" Rochester 2bbl. I could change over to a Holley 4412 if I went to other tracks. We had to run the ram horn manifolds for years then they finally went to headers.