my 750HP (the one with no choke, double pumper) was dead on for my almost 440, eddy headed big block. it was just a touch lean at WOT, so we went up 1 size in the rears for insurance to make sure it didn't go lean on the street.

we didn't touch the idle circuit at all, and it idled great at 700-800 rpm, AFTER the engine was fully warmed up!

however, I'm thinking i need to upgrade to a 50cc pump shot, because we didn't tune off idle response, they slowly brought the rpms up to 3,000, started the dyno pull which lugged the motor back down and they slowly gave it WOT, so we never really tested WOT from idle, and it's got a bit of a stumble that I can drive around by feathering the throttle (and pumping more fuel)
or waiting till I'm rolling around 20 mph with 2000 rpm or so before mashing it.

I'm just too cheap and haven't gotten around to it yet