I went with the al G3R and it's held up to a lot of bad driving or inattentive driving. I don't have any exp with the CF G3R but I thougth I read TDC57 has some of the CF break on him. Haven't checked into anything for the 3905 tranny conversion/mounting plate, but like arct1k said they are the same for the tranny mounts. If your going with the G3R you might as well go all the way and get the G1 tranny with the FLM Alum half. You can do the same conversions on it as far as the revo shaft and slipper and it is strong and looks damn good on a dirty G3R.