Your right about these being the only legal aftermarket alloy pre75 arm Firko.....the other arms like DG etc where chrome moly......mainly for the jap bikes as there std arms where heavy steel. It's not right when you see those Thor arms and other later made arms on pre75 bikes. As far as I know the Thor arm didn't get made till 76 and that's when a lot of Suzuki RM's and CR Honda's got them fitted. As far as those KLP arms go, well they just don't fit into VMX in my opinion on anything.