F/U Pertronix Ignitor

I am thinking that the GM HEI conversion would be easier and cheaper for parts and availability.

Can't sway I agree. It doesn't get any easier than removing your points and bolting a Pertronix directly in place. You don't have to pull the dist. if you don't want so there's no need to adjust the timing (I know that only takes 5 minutes but it's still another step). The first Pertronix conversion I did took me 20 minutes. As for performance, unless you upgrade the stock HEI module to a performance one the Pertronix has to be at least as good. Sure the HEI puts out a lot of voltage but voltage isn't everything. They start falling off (misfiring) quickly above 4500 rpm. Yeah an HEI module can be bought at most any parts store whereas the Pertronix can't but with the Pertronix system you can also change it back to the original points system as quickly as you could swap a HEI module so all you have to do is carry the original points and condenser in your tool box.