421 sbc AFR 220CC heads, ported super victor intake, Pro Systems 1250 carb, looking for carb spacer recommendations. 1" ? 2" ? none? Thanks,

It's possible that you might need more plenum volume but only testing can tell you for certain. Nobody's combinations are the same.

My 388 likes the APD tapered 2" spacer but I haven't done an ABA on the same day test to verify how much.