Well my question got lost amidst the chaos:

Whats the difference between the green buggy and black truggy outdrives? Are the black outdrives just made out of a harder metal? My truggy needs new rear out-drives and I have a crap load of buggy outdrives.

EDIT:

Hmmm, I see Losi did a running change with the outdrives. LOSA3505 in the manual leads to the HD outdrive set.