Custom trike rear end??

[BLAQUEHAWQUE]

What rear end can be used in an inverted position (to reverse rotation) ?
Should be close to 3.09 ratio.

Are there any rear ends that allow flipping just the ring and pinion?
(I did it once on a VW that I put a Corvair engine in.)

 

[Chumbly]

Supposedly the one in my trike is flipped. It's supposed to be out of a '80s Mustang (I hear). Not sure on the ratio or if they'd done anything to the diff before putting it into the kit.