RE: KAOS AND RELATED PLANES AND INFO
My ultimate has Robart retracts, with a ASP61 for power. The only suggestions I might have are, if you install retracts, beef up the engine firewall a little with glass cloth. Because of the long tail moment on all Kaos', keep the tail light. Your 91 should do an excellent job. I imagine your 4 stroker weighs a little more than my 2 stroker, so you probably will be able to mount the air tank, if you use one, behind the wing saddle. Good luck.