The factory location is from the forward location on the rear axle tubes to the inside of the frame rail, to a quasi-mount. The 3/4" bolt goes through the frame rail, through the mount & into the upper shock mounting eye. From top-to-bottom, they slant rearward, to the axle tube. The leaf block cross-section looks similar to a piece of train track rail with a cantilevered haunch, acting as a bump-stop. I may have a few good photos of this assembly.
Here is a link to an auction on eBay for the correct rear shocks:
Rear shocks I have purchased & installed these and they have proven to be a good value, considering the price, fit, finish & performance.