Carb recommendations???

The formula to convert flow for pressure differentials is;

The orig. flow /by square root of (Orig. depression /by the New depression)
This can be used for head flow, BUT if the original test depression is too low,the
results will not be accurate.The poorer the design efficiency, the higher the error
will be,try keeping the conversion in the 20"h2o to 28"h2o range.Some testing
was done at very low #s, 5&6" range, way too low.Most have come around to
using 28" which Smokey Yunick determined decades ago to be the most accurate
correlation from bench to track.

As far as comparing 2bbl and 4bbl, I don't need to be careful at all. The ratings were
arbitrarily chosen strictly based on intended usage by those doing the choosing
at the time.If you are determining the flow and performance capabilities of any
prospective carburetor,they must be compared on common turf, and depression
is parameter #1.