tire ballooning in the rear, but not front...

actually, i was interested in putting that cd in my maxx but i haven't moved on it because of the plastic cup.
the way i see it, if plastic wasn't good enough for the cups in my diffs, it wouldn't hold up in the tranny either.
when FLM (or anyone else) makes an aluminum cup for that, i'll jump.
anyone tried it with brushless?