I asked this question on an S10 forum that I'm on, but no one seemed to know. I'm told that '88 and prior years S10s have rears with 7.5" ring gears and 26 spline axles, which I have. In '89, they changed to 7.625" ring gears, with 28 spline axles. The housings appear to be the same.

Is it possible to put the 28 spline axles from a 7.625" rear into a 7.5" rear simply by changing the axle and spider gears ? Would the diameter of the axle where it runs on the outer bearing be the same ?

Thanks for any information, Ron.

You can put the 28 spline axles into the older housing that had 26 spline axles, but you must change the differential. You can't just change the axle gears because they redesigned the differential when they went to 28 splines. The axle bearings are the same size. Notice that the rear end from a 4X4 is about 4 inches wider than the rear end from a 2X4, so get the parts from the same one that you have.

I knew that you would know big gear head ! Thanks for your help, Ron.