The best throttle performance is progressive. The best full-throttle performance is different. In theory. Some say the non-progressive is better for full-throttle. But it all depends.

SUs are variable venturi so are hard to compare on paper to a fixed-venturi carb.

I was suprised to hear L18_B110 say the 32/36 was considered superior to twin-38mm Hitachis. But he knows more about racing than most of us.

Still, for all-around perf many have said they favor the twin-Hitachis. They work well at low, medium and, high throttle openings.

But why bother? Just go for twin-2bbl sidedrafts. They look great, sound great and work great.