Rail Power never had a -2.The new type shells come from Rail power tooling (better detail I believe), they have enclosed the pilots (so you'll have to grind down the coupler box on the frame and drill it, as that is what holds the shell to the frame), But other than that, it should be no problem to swap it out. I have swapped 1 sd40-2 and it took a little work to get the coupler pad ground down and level, but works like a charm.