For reference...... original B1’s prepped by Koffels.
Bowl and chamber work only:

28”, 4.375 bore, clay radius entry, no tube on ex:

Lift———in/ex
.100——78.9/58.5
.200——148.0/106.1
.300——216.0/146.4
.400——275.6/187.1
.500——326.1/219.2
.600——357.7/242.6
.700——378.4/257.7
.800——389.6/266.4

These made about 830hp on a 526 on our dyno with a single 1050 carb.

Dyno numbers aside, I think a cam swap and the single carb manifold would have improved the ET.