any of tha three will work on any 7 petal front (2.4/2.5 any age) with a little massagin' (oblongin' of tha mounting holes) and modifyin' those extra large ports on tha one reed plate.. age is tha main difference in tha design.. tha cross drillin' makes tunin' those a pain in tha a$$ sometimes and don't really do much...