first of all your looking at an airplane engine, not one designed for a monster truck.... they don't spin too fast either, that is why the lower output.... you will have to regear the cen to work with that.. probably go much slower... what kind of problems are you having with the cen engine?.. my experience with them is pretty good... cooling on the GMS engine will be a major issue.. very small head.. designed for airplane.. prop wash and cowl cooling is how they work... Would be interesting to see how it works, but don't expect alot... the other issue would be exhaust... the GMS uses a muffler attached to engine.. the Genesis uses a tuned header and pipe.. rear exhaust.. alot of issues finding the correct size.. I would look into a .30 OS or cheaper SH or something like that.. at least you get the proper RPM's and mounting...