i had a hard time dialing in my carb so i got a wideband o2 sensor to get it dead on. i have 225 slant with 4 bbl intake cliffor header 3in exhaust,port polish head, larger valves, custom ground cam .502 lift. i have a 650cfm edlebrock mechanical sec. just wanted to let people know my jet sizes to help tune: i have 89 primary with 65/57 metering rods. with 101 secondarys. i have 8in vacuum springs on the metering rods. and the pump shot on the richest. the secondarys are a little lean when first kicked in.
hopefully this will give some of you a starting point

i had a 390cfm holley on it and it just never ran right, top end wasnt there like with the 650.

i found the same thing with my 390cfm verse a 600cfm holley, .528 lift cam.