Quick Fuel Technology slayer 750 lean on 383. rejet, holley jets?

I just bolted one of these on my 383 vortec, i had to turn the idle mixture screws out to 3 turns to make it run desent at cruze without missing, this of course made it eye watering rich at idle. Base jetting on the primarys is 72s, i picked up some 74s and 75s. and hopfully i can get the idle mixture down to 1 to 1-1/4 turns out. i was suprised when the parts guy handed me holley jets.
Anybody out there rejetted the 750 slayer and how'd that go? comments welcome on this carb it's new to me.