Holley stumble trouble

I’m still fighting this God-forsaken stumble! I’m on the verge of throwing this damn carb off the bridge with glee.
I’ve tried initial timing all the way from 22 to 10 degrees btdc with multiple curves to 30 - 38 total. Still stumbles on the transition. I’m all the way up to 75/77 jets, 28 squirter on blue cam in #1 spot. Still has the 10.5 pv in it. (Cruise vacuum is 14-15”). Tried wires in the IABs with no luck.
Would a vacuum leak around the throttle shaft make this ***** untunable? While resetting the acc pump arm I noticed gas leaking around the throttle shaft. Maybe this girl is just totally clapped out......
I don’t know what the hell to do now. See if I can borrow a known good carb from someone to try I guess.