The Saito fits completely inside the cowl, but I still cut out some of the bottom and also a hole in the front for cooling. The only problem was that the length of the engine forces you to mount it at the very back of the rails, and the lower right mounting screw gets in the way. I had to find a pan-head screw to use for that hole to get the proper position. Other than that, it was one of the simpler cowled installations I've encountered.

BTW, I got a lot of good flights in today. Got the low end adjusted better and the Saito smoothed out a lot. I don't need over half throttle for anything, but it sure is fun pointing it straight up and watching it rocket up...