I have a set of US Strange 3.73 gears for a 12 bolt rear. These are for a series 3 carrier. Bought the Strange Engineering rear with these gears and only ran for about 1500 miles. Decided to install 4.11 instead so these are for sale. Gears are in very good condition.

$125 shipped firm

Strange part #RS01888373 (cost is $213.69 + shipping from Summit)

 

Well... doesn't look as though anyone is interested.
Guess I will have to put them on Ebay in a day or so.