The lean is fixed... sort of.
I had a day off, so I figured I'd swap the leaf springs like I originally planned. Had nothing else better to do, and I couldn't help but wonder if the used leaf spring I got from a salvage yard was weak.
First thing I noticed when I took off the passenger side one was... wow, it was much more of a pain to get off then the driver's side. Much stiffer! So I thought that was a good omen...
I switched them, and measured the rear wheel well height on my level garage floor. The same!!! The front was still off by 1/4", but I thought I had cured my lean in the back!
Took out for a drive, came back... and just over 1/4" lean now, front and back. The leaf spring must have settled a little. Its better though, you almost can't tell from the back that its leaning anymore.
So, my last post in this thread will be after the coil spring is installed later this week. That will hopefully fix the lean altogether. Thanks guys for all your help! You saved me some $$$, telling me I could do this myself with common tools, and you were right!