i'm pretty sure the only thing they share in comon is the transmission style, spur gear setup, engine and clutchbell setup and there both made of a flexible poly plastic and maybe a few little things here and there. with both spur gear setups being the same that gives some gearing options, other than just the cutchbell, though. like the 39 tooth spur, 45 tooth and the 43 tooth spur gear. I think those are the 3 gears if i'm wrong please interject with the appropriate gear tooth, lol, i'm using my phone so I can't double check the teeth specs at the moment.