[cameron02]

Cant remember how many mm. 40mm dosn't sound too bad. I think its better to measure in degree's (cant spell), maybe using a digital spirit level if you can borrow one. Try asking Peter at DRB he will know for sure.

Apparently the greater the angle the more power lost. But no angle = uni joint lock. So idealy you want a few degree up down and a few degree across but no more than necessary. That's about the total of my knowledge on the subject. I'd contact DRB if I were you.