New Carb

Hey guys, Looking for some opinions on a new 4 barrel carb. Engine is a 318 with a 904 trans, mild cam, stock 318 heads, 340 intake p# 3671918. Hooker headers to full 2 1/2" dual exhaust. Currently has a holley 8400 650 carb with vacuum secondaries this carb really doesn't seem to fit wellI've been having some for issues between the carb flange and the intake. I believe the original carbs that mounted to these intakes were TQs? Looking for something that will fit well onto the intake manifold in the 600-650 range with vacuum secondaries. looking for some input.