Who makes parts for these still?
Looking to rebuild my Posi and swap to a 3.90 to 1 gear this winter.
Car has a 3.42 to 1 posi now.
Would I need to change carriers?
Cheaper to build a 12 bolt or 9inch?
Currently running high 1.50 sixtys on a footbrake launch, pushing about 3350 LBs.
Thanks for any and all input/ input.

 

Check with Jim (monzaz) or Brian (507OLDS). They should be able to answer your questions and point you in the right direction.


John

 

It will cost similar money to build whatever rear you choose, if going for strength and not just a rebuild of something that is more or less stock and for which you already have most of the stuff. If you are runnikng 1.50 60 ft. times, either a fully built 12 bolt or better a Type F ten bolt (aka "Dearborn" option or 9" Ford) would be best.

 

You do not have to change carriers.

 

Do a 12 bolt Chevy, good for the 9s and cheaper than a 9".

 

Cool. Thanks for the info guys. Probably gonna look into getting a 12 bolt built.

 

I have access to a 12-bolt Chevy housing that I can build to suit.

As far as your O-axle,you can retain you existing carrier,and install new Richmond 3:90 gears,but you will need to mill .100" off the backside of the ring gear, OR you can leave the ring gear alone,and get a new carrier,which is made for the Richmond gears.

 

If you want my .02 cents, go with the 9" I like being able to change gears completely without changing carriers, just cut it down to size with 12 bolt bearing ends from moser so you can put your gm brakes on the end.

 

After this past weekend of racing and running 1.55- 1.60 sixty foots and running 11.64 to 11.55, I'm just going to keep the same setup for awhile.

I dont think a gear swap will really make a huge difference for the cost.
Probably gonna drain the rear, clean it, put Amsoil back in, and add a W-27 cover.

I think a year from now I'll start build a new rear. Probably go with the 12 bolt. I'll be starting on a new engine build by then with MORE HP. BB stroker or atleast new rods pistons with more compression and a roller cam topper with a victor intake. We'll see what happens.

 

When you refill that rear,use conventional gear oil.Do not use synthetic.It is not good for any clutch style posi unit.Don't forget your posi additive too.