First check to see if it has ball or roller bearings on the crank. Some of the Macs I've come across use roller bearings which are not good for airplanes. As far as the ignition, it usually doesn't work out well to make a new bracket for the coil, and anything that would work well would end up being heavy. Switching to battery powered CDI would be better all the way around, and they only cost around 50 bucks or so now.

AV8TOR