RE: OS .35AX
I have been running my 35AX on a GP Combat Spitfire for several weeks now. It is currently stock. but I live in Houston, and Jett Engineering is just down the road (Muahahaha!). I haven't tached it yet, but I can keep up with my buddy's GP P-40 with a OS 32SX and MACs pipe. the 8x7 APC is absolutely the best prop. I am currently fiberglassing my Spitfire, and I will run it with the stock setup, and then the Jett muffler.
Overall, I have been very happy with the stock setup, but of course I need more speed!
Report back soon.