R = revo.
G2 & G3 = for emaxx 3906 tranny
G4 = emaxx 3903/05/08 tranny
G2r & G3r = 3906 tranny ( revo front & rear ends )
Difference between G2 & G3 / G2r & G3r = thicker upper & lower chassis plates, X-braces not hollowed out underneath to improve strength ( didnt really work, trust me.. ).
