10.5 power valve ???

Has anyone had to run a 10.5 power valve in their holley ? I just got my 340 back together and have been running it for a few days now. Was running great with an out of the box 770 street avenger but I room that off to use on my fresh 383. I tried to match that carb to this one I got from a buddy. Perfect off idle, perfect WOT, been fighting a lean stumble during throttle tip in during cruising. 12" vac at idle, 14-15" while cruising steady. AEM 750dp, pink cam up front with 30cc pump, 31 nozzle, 50cc secondary with 35 nozzle. 65/77 jets. Originally started with 4.5 power valve and was not drivable. Going by holley guide I went to 6.5 according to my hot idle vacuum of 12". Still had a nice stumble at same spot. Drive with vacuum gauge and notice the stumble happening around 7-8" vac so I ordered an 8.5" power valve. The stumble is so close to being gone but still there. Before I order a 10.5 PV, I figured I'd ask those with more experience than myself ..... would a 2" quicker enrichment cure the lean stumble? Stock bore '70 340, eddy heads, comp .484 cam, 4spd... 18deg initial timing, starts and idles great, prefect throttle response from a stop ....