Anyone have a clue what the difference(s) are between these 2 fork tubes?
You might check with Custom Cycle Engineering.
Both are 39mm.
Looks like they are designed to use different lengths damper tubes, 7'5" vs. 9".
Maybe I just just have to buy the -09's for safe fitment of a set of Progressive Suspension Monotubes, since those seem to depend on an exact inside length of the fork tubes.