Power Valve Selection

Hello,

So like the title suggests, I am trying to narrow down my power valve selection.

The car is a 70 charger, 440, 727, 3.55 rear. The cam is the Comp Cams XE274H-10. Running stock heads, intake, exhaust. The carb is a 750 Holley with vacuum secondaries, 64 jets, and currently an 8.5 pv.

Now I do know that there are a couple ways to select the power valve based off of either the idle vacuum in gear, or the cruise vacuum halfed - 2. So I know the idle vacuum in gear is roughly 8-9 inHg. cruise at 50-70 mph has the vacuum at 18-19 inHg. So I think I am close with the pv, but it may be coming in a little soon. based off of the 18-19 cruise vacuum I should be having a power valve of 6.5-7.5. Is my line of thinking correct?

My biggest issue with the car was I had it out a couple weeks ago and floored it from a stop. I was not met with spinning tires but something that may have been a stumble or a bog. It finally got over it and off we went. Well I tried it again last night and the car spun the tires no issue. My initial thought was coming off idle I had the squirts and the power valve dumping too much fuel in. But it appears that may not be the case. Other than that I think in other driving conditions the car performs pretty well.