I am building the VectorFlight Edge 540 (an awesome ARF) and am going to mount a SATO 91 on it. My question is how far should the front thrust washer be from the firewall? It looks like 5.25" is good but those of you with experience might point out a different distance because of balance or some other reason. I wouold be glad to hear from those of you who have completed this aircraft and any suggestion you might have. I have already change the tailwheel assemble to a much heaver one than the one supplied. John