RE: Can you tell me
I think one has more or less teeth on the gears.
02076 is stock for the Lightning ----> comes with 02041 (39 Tooth gear) & 02040 (44 Tooth gear)
06034 is stock for the Tornado XL ----> comes with 06033 (42 Tooth gear) & 06032 (47 Tooth gear)
but both transmissions should fit the XL to convert to 2 speed and as far as I know, the gears are all interchangable.
Mark