Looks to me that you already have the correct prop? 8200 rpm is a pretty good sweet spot for your engine.
Lee MRC
"As an aside I can't help but notice your signiture, are you active on the air and if so what freq's and times? I have really been enjoying getting my orginal AM rig back on after about 25 odd years and meeting some of the same people that I flew with in Midland, Texas. It is amasing that after all of these years we still hold the intrests."
I Don't get on the air anymore. I'm on RCU all the time. I sawed my antennas down. Still have a Yaesu FT901ZD and a Dentron MLA 2500 amp. I remember talking 48 states AM on 160 before they opened up the band. That was fun. I was mostly a 75 meter rag chewer. I have a ICOM 2AT all stuff from 25 yrs ago.
Enjoy,
Jim