Hey, last year I bought a California Sidecar Friendship III (2 seater) and attached to the 08 Ultra. By fall, had it dialed in with the parts I had. The only way to mount CSC was to reverse the 45* and 70* (*=degree) Bosses, but kept Clamps in correctly. Problem was the axle to axle is 15 1/2", and made it a workout on right hand turns.
So, figured winter project! I moved CSC back to 10" axle to axle so I could see what Parts are needed. Now, the front 45* Clamp will Not work, not even close, about 6"too far back at that angle. And a longer mount won't help either.
So, now I reversed the Clamps, put the 45* on back with 70* solid steel Boss. And 70* Clamp in front, and have to order longer 45* Boss.

Question--Does it Matter where Boss & Clamps go as long as everything fits good?

 

Answer, from Jay at DMC. It Does Not matter if 45* or 70* is front or back as long as both Boss & Clamps are the same.
So I ordered a 19" long 70* Boss for front lower. Also order a shorter Strut for upper rear mount because while moving sidecar back, I also moved sidecar in closer to Ultra. Hopefully it works, and sidecar in enjoyable Later-