REXRACER, I flew a H-9 AT-6 with a Saito 82 and I could easily keep up with my buddies Corsair and Mustang with OS91 4-Strokes. The only thing is that I could not fly as large a loop as they could till I used up about half the fuel. Actually I could have used a much smaller fuel tank that the stock one and still fly 12/15 minutes with plenty in reserve. I used an APC 14x6.
Fred