I think your jet spread is to big unless your power valve fuel holes in the metering blocks are real big
I think the old adage of having 6 # bigger jet size in the rear (#72 front with #78 in the rear) with no power valve is a good place to start
I am also against opening throttle shafts enough to expose the transition slots on any Holley type carb
On the idle mixture screw initial setting I start with two full turns out from GENTLY seated and adjust from there