acceleration issues

Measure your vacuum at cruise rpm. I'll bet it's up in the 13-15" range. You need alot of throttle opening to get down to that 4.5 PV. I would suggest trying a 6.5/7.5 PV. Wont effect your idle and you'll have enrichment sooner when at cruise rpm.

The 1/2 idle vacuum power valve, that Holley recommends, works well in idle to full throttle situations but in real world street cruising you need a little higher # PV opening rate.