please check you information before you go misleading the family of GO engine users Ruune as the diameter of the rod hole for the crank pin on the GEN 4/5 is 4.7?mm & the newer rod diameter is 4.93mm, so while the newer rod will fit the old crank it doesn't last long because of the extra play & leads to disappointment due to poor engine performance & a much shorter life.
hence if herb99 buys the new, lighter & balanced, crank & rod he'll be another happy GO engine user with an engine that really rips.