A friend out in California about 40 years ago used a converted flathead Ford V8 engine to power his portable sandblaster. When he needed more volume, I helped him install a 4" stroke Mercury crankshaft and pistons to replace the 3 3/4" Ford crankshaft. The Mercury engine from 1949-53 ran the longer stroke crank, which could also be offset-ground to 4 1/8" by using the 85 HP Ford rods from the late 1930's flathead V8's. 4 1/4" stroked shafts could be made by welding extra material onto the rod journals and setting up the crank grinder for the longer stroke. Those grasscutter strokers had a nasty habit of twisting the center main bearing in two at high RPM and hand-grenading the engine.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!