Hotchkis leaf springs sagg brand-new

You are not stock shackles. Leaf spring shackle angle between the bolt centerlines are susposed to angle back. Straight up and down is acceptable. But not preferred. See page 166 of the Mopar Performance Chassis manual.

Put the stock front hanger back on it and it will raise the rear 1"

Now check you pinion angle. You will most likely have to adjust it with angled shims. If you run the Hotchkis lowered front shackles you will really probably have to check and change the pinion angle.

My A-body with Hotchkis springs and stock shackles: