The OS 91 4 stroker should work good as far as power is concerned. It will take alot of material removal on the bottom of the cowl, and alot of lead in the tail to compensate, which will increase your gross weight and wing loading. just be careful of the CG. AS a previous poster said to me.. My plane may still be a bit nose heavy from the bigger engine. just a habbit of mine I guess. Nose heavy plane fly's poorly. a tail heavy plane fly's once. or as I call it. a smoken hole of toothpicks. better to error on the side of caution.

FW