Hey guys,
My 91 RS has a 2.73 Open Differential w/ drum brakes.

I have a choice between two rears to put into it. I

1)9-Bolt 2.77 Posi w/ disc brakes

2)10-Bolt 3.73 Posi w/ drum brakes


I am leaning towards the 10-Bolt because its almost impossible to find a 3-Series carrier for the 9-Bolt. Whatcha think? Am I right?

 

I would go with the 10 bolt. Parts are easy to find, and the 3.73's will give you a great sotp difference from the 2.73's.

I went from 2.73's to 3.73's and love it.

 

Thats what I tought. Plus with the 10-Bolt I can put it in right away. I dont have to mess with getting parts to do the disc brake conversion before I can put it in!

 

yeah, with some help, you can do the swap in a couple of hours. Depends on how rusted the bolts are on the rear. And how long it takes to bleed the brakes.

Might want to check the condition of your rear spring and shocks. Would be a good time to replace them. Also new LCA's and relocation brackets would be nice.

 

I'm not sure if you're interested or not, but most people recommend 3.42 gears for a 305 TBI. Those gears match up better with our cars, from what I've heard. 3.73s are usually a little too steep for that set-up. But, of course, it is your car.

 

Yeah go with 3.73 posi, my friend has one in his 305 TBI and he sure does spank me now. I didn't check, but you might want to look into exhaust and intake to free up the setup a little more.

 

Ive already got exhaust & intake. Headers, High Flow Cat, Flowmaster Cat-Back

THE CAR SOUNDS GOOOOOOOOD!!!!