I need to do something with my existing rear-end. It's a 10-bolt posi w/ drums that the previous owner had changed from the stock 3.08 to a 3.73. When I first bought it, I had the speedo calibrated for the new ratio for a ridiculous price ($315).

Anyway, the 2 things that I need are a higher ratio (for street use) and disc brakes. What is my best bet? I know I can swap the gears in the read end and do the drum->disc conversion, but I'm not sure that's the smartest thing to do $$$-wise.

Any suggestions? Also, I see that there are both 9-bolt and 10-bolt rear ends... which one is more desirable, any why?

Thanks in advance!

 

The 9 bolt is desirable because it's stronger however parts are non existent making the 10 bolt a more preferred diff.

Dropping down from a 3.73 gear set back to something like 3.08 will probably mean a new carrier also. The 3.73 should be on a 3 series carrier unless a special gear set was used. The 3.08 gears will need a 2 series carrier.

Best option? Find a complete 10 bolt diff with disk brakes and the gear set you want and swap it it. Sell the old one. Swapping the entire diff is easier than swapping the parts around.

 

Great info, thank you.

Are there any good resources outside of this board I should be looking at to find one?

 

I think you could use 3.23 gears which would work with the 3 series carrier.