acceleration issues
Lean into it? As in slowly rolling into the throttle or mashing it to the floor.
If it's a slow press to floor, PV opening too late may be your issue as Oldmanrick suggests. Might even want a 10.5 pv.
If it's mashing to floor, accelerator pump shot, especially if a DP. Vacuum secondary, then the spring is too light.
I'd put the jetting back to 70/80 range if it's a 750. 66 is REALLY lean, my 340 won't even run on that without surging badly.
What's the initial timing set at and idle speed in P/N and in gear? I'd want at least 14* initial and depending on cam anywhere from 800-1000 rpm in park.