might want to rethink the fuel pressure at the needle.

my duel feed 3310 will handle a little more psi than my single feed side hung float/bowl 1850-3 won't.



I had some issues kinda like that with my last 1850-3 600 cfm holley. had 8 psi and would over power the needle/seat, cut back to 5 psi and its all good. the 3310 and 6213 800cfm spredbore worked fine with the 8 psi

I converted it from a 4160 to a 4150 replacing meter plate with a meter block then added a QF adjustable vac pod to dail in the sndarys

fixed that little carb up and works great on a 318.

I used a regulator to cut psi down from 8 to 5 psi with my mech pump.