I have an 89 RS. I need to know if it is a 10 bolt rear or not and what spline axles it has. It has rear drums.

Don't say "look under the car and count" as the car is off site and not readily accessible.

I believe it is a 26 spline and a 10 bolt but need to be sure.

Thanks

The RS didn't come with a 9 bolt so if the diff is still factory stock it will be a 7.5/7.625 10 bolt. In 18 years, anything could have been swapped in.

More commonly the 89 will have 26 spline axles. A late 89 build date may have 28 spline axles. 1990 was the change over year and a few of the late 89's got the 28 spline axles. Assume they're only 26 spline.

Gear ratios for the 89 RS

2.8L V6
Manual 2.42
Auto 3.42

305 TBI
Manual 3.08
Auto 2.73

Excellent............thanks. Just wanted to be sure.