Just Picked up a set for my '99.

I see everywhere the diameter to open up the wheels is 4.774.

But this is for the AAM built rears of the 3rd gens. What about the Dana 80. I know they are close but exactly the same,,, I doubt.

What Should I open up to +/- 0.005" tolerance?

.

 

If you have the rear on your truck then just measure it. Or machine them to 4.774" and try them. Are you doing your own machining? I've done 4 sets for friends, all 3rd gens though.

 

I milled mine to the point where the small inside "lip" was gone. I used a rotozip. Easy project....I just need 2 more 3rd gen caps.