my spider and side gears went out so im fixing to swap my 28 spline out for the 31 spline expo rear end. iv e got everything, ready to make it happen, but im wondering what angle to set the pinion at. having no luck with the search.
in not sure how much lift i have on the truck (done by previous owner), but i know it at least 2" (blocks/pic below).

so should i set it perfectly in line with the driveshaft, or should there be an angle there?

 

 

That's a factory two inch block actually.