I have a 1997 Dakota Sport with a 8.25 rear end and all I can seem to find is 9.25 rear ends. What is the difference between a 8.25 rear end and a 9.25 rear end as far as mounting? Are they interchangeable. Will they mount up the same or is there a difference in the mounting?
P.S. Gear ratio is the same in both.

 

What are you planning on doing a swap? The 9 1/4 was used in all kind of vehicles starting in the early 70's. Spring perches and over all length along with yoak sizes change from year/vehicle. Same is true for some of the others. If you are planning a swap make sure the spring perches and over all length are the same as the one in your truck.

 

The 8.25 is in my 97 Dakota Sport. The 9.25 is coming out of a 2000 Dakota to go into the 97. Will it mount up?

 

Are they 2wd or 4wd.

You need to match. The spring perches are different between the two.

You might have to mix/match u-joints at the differential to get a match.

 

It's 4 x 4 the spring perches are definitely difficult? I looked them up and they looked the same.

 

If both are 4x4's then it should bolt right in. There were changes to the yoke on the differential that vary by year.