hello, after rebuilding one of these for a customers airboat would make a realy nice airplane engine. Its half of a ford 460 big block. stock form has aluminum block and iron head but any aftermarket head for a 460 big block ford will fit. so lots of aftermarket support. also it was used as engines for midget race cars and has a centrifugal water pump driven off the timing gear, and has a stator type alternator directly behind the crank pulley. http://i138.photobucket.com/albums/q272/thoriated/random/mercruiser224.jpg and here is the page with a lot of info. The elusive 224/3.7 MerCruiser banger - THE H.A.M.B. oh and to make it even better it has a chevy bolt pattern. with a good aluminum head, good intake manifold, and good exhaust its one potent combination and direct drive was enough to push a 3 seat airboat to run on dry ground. Would be realy good candidate for aircraft use because of no belts to drive water pump or alternator.