I too had to shave a bit off my RPM arms to fit the FLM tranny for the Slash. They did fit the stock setup though, so it's hard to blame them for that. Actually, that's probably more FLM's fault now that I think about it. I don't mind doing some light mods to get something to work, but sure sucks if you are out bashing/racing and get a replacement at the LHS on the spot if I break something because I rarely tote my dremel along.