So, 9” @1400, in neutral.......@50* timing.

Imo, you should put the timing at a more “normal” place(like38*), redo the vac test, and reset the mixture screws.

The goal is to make it run right with normal timing....... not 50*.

With less timing(and theoretically less vacuum), I’d expect to have to richen up the mixture screws.

QFT sells a secondary throttle lever that has a screw on top so you can tweak the secondary blade position with the motor running.

It just replaces the original one....... takes about a minute to install.

I’d buy a package of really small Holley air bleeds...... that way they can be drilled to anything you want.

The 24 hsab should be fine, but the 70 iab is on the big side for that combo.
I’d start out with something like a 60.

Actually...... I think I’d be getting out the garden hose before I went any farther.