V6/Predictor Prop Advice needed

[83PREDICTOR]

I am going to be sick tomarrow so I cant go to work. Anyway, I am going to try to borrow a prop form a local shop.
What should I try to get? I am running 6450rpms with a 21P POS at 63mph
I woulds like to get 70mph or close to it with good hole shot.
Any and all thought please.

 

[Blizz]

try a chopper if he has one, holeshot will suffer but will net higher speeds. 26-28 as they tend to slip a bit.

 

[Vandalizer]

Based on what you're seeing right now, I'd almost start with a 23P. That should get you real close to 70, and keep most of the hole shot. Here's where I looked-

http://www.go-fast.com/Prop_Slip_Calculator.htm