RE: CH Ignition conversion on G26
Though somewhat smaller in size a 16x8 prop produces pretty much the same load on the engine as a 18x6. Ideally you should break in an engine using a prop one size smaller than normal which in this case would be a 17x6 or a cut down 18x6. After the engine has had some amount of run time and fitted with a less restrictive after market muffler it should be propped to run in the 8,500-9,000 rpm region as that is where the G26 really shines.
Karol