Differential 101

eastmedia · Post by **eastmedia** » Sat Aug 06, 2005 1:42 pm

What is the difference between the 1600 rear end and the 2000 rear end? I've run across many posts about 3.7, 3.9, 4.1 etc.. rear ends but can someone explain what this all means?

Is there a part of a 2000 rear end that can be put into a 1600 to increase freeway speed, lower RPMs at speed, etc..besides switching to a 5-speed?

thx all,
Ron

Post by **spl310** » Sat Aug 06, 2005 2:19 pm

The stock 1600s came with a 3.89 rear end gear ratio. The 2000s came with a 3.7 gear ratio. There are rumors of a 4.11 being optional on the 1600, but I have never seen one.

The ratio is how many drive shaft rotations to get one wheel rotation. By moving to the 3.7 out of a 2000, you will reduce your freeway RPMs a little at any given speed over the stock unit in your 1600. The math guys will have to do the calcs to figure it all out for you.