[LudwigTheMad]

higher flow fuel pump....also you said you replace the carb....what fuel pressure does your new carb require...

for example holleys like 6lbs and quadrajets like 8lb....or is it the other way around????

you also may just need to adjust your carb....this can be done with a vacume guage or by ear........i

If you use a vacume gage, connect to a steady port (lower side of the carb) and adjust your fuel mixture, reading the guage...when it starts to go down, stop go the other way, when it starts to go down again, turn back till you have the highest vacume-then your adjusted proberly.

after you do this, make sure your idle is adjusted back to normal and repeat your check.

otherwise make you mixture a little richer (small turns) and see if it stops....sounds like you mixture is to rich....(carb backfire is too lean.....regular backfire is too rich....someone double check me I might have that backwards....as personallity #7 seams to be strong influance today)

by the way #7 is the backwards one.............I think