yeah rep, they're aluminum, check www.rc4wd.com

O'donnell is in every way superior to Blue Chunder...i ran blue thunder for about a year, and switched to O'donnell...

the difference in power and running temps is incredible...even the blue chunder "race" blend runs your junk way too high of temps. it's REAL oily. O'donnell is the way to go.

also, the HPI nitro MT is easy to work on, easy to maintain, and tough as hell. you'll love it.