12 bolt gears
 

I'm about to put together a rear end for a friend, it will be a 12 bolt positraction thing for the street, but all we have are 4 series posi units. Does anybody make a 3.73 or so gear for the 12 bolt that fits the 4 series unit? We're very aware of the 4 series gear sets that have a very thick ring gear to be used with a 3 series carrier, but we are going the other way, with a 3.73 or a 3.90 gear set.

Re: 12 bolt gears
 

Richmond makes them, or at least used to.

Re: 12 bolt gears
 

US Gear # 01-888373-4 Put these in my Chevelle. I've installed three sets of US Gears and have been very happy with them. Only ring & pinions made in the USA.

Re: 12 bolt gears
 

I think I have a 3.90 at home that only has a couple of passes.