I got similar results at similar speeds with:
Dual single-barrel Rochesters (too much "carb"/flow at low RPMs) - rebuilt by whomever JC had rebuilding carbs 16 years ago
Dual progressive two-barrel Carter-Webers (no significant "power" at higher RPMs - new from Langdon
Single two-barrel Holley AA-1 (with adjustable jets) - rebuilt by a professional who has a good reputation
