Christopher Carrico is a diehard Pro Systems carburetor fan.  Heres a summarized E mail he sent us recently: 

We've won 5 Jegs Superquick Wallys in the last 2 seasons, after switching to Pro Systems carbs.   Our latest 632 tunnel ram engine made 1334 HP on the motor and is deadly consistent!!!!   But your single carbs are wicked as well, our little 555 is no slouch either making 1121 h.p. on the engine with your 1600 cfm carb!   Both combinations win races and of course allow all these Wallys to set on our shelf at home.

Thanks Pro Systems!