[Rd regal]

Update: As there has been no helpful responses and in the hopes of helping someone else that may attempt this someday, I can tell you the following:
You'll need the right rear engine / tranny mount from the Lesabre. The left tranny mount works just fine. You'll also need to use the right front axel from a Lesabre but you'll have to use the outside (strut end) Regal CV joint and boot as the Lesabre end does not work with the Regal hub. The old left front regal axel works fine

You'll also need to use the oil pump / filter adapter from the Regal. The Lesabre one will locate your filter directly inside the front frame of the Regal
Water pumps are plumbed a little different, you'll need to change pumps or adapt the heater hoses to route them correctly.
You'll have to relocate the cruise control of the Lesabre engine. It's in the way of the Regal master cylinder in it's stock mounting location.
There may be other Little minor tweaks I've forgotten about but nothing needing more than a few minutes to correct / change.

I now have it all bolted up and sitting on all 4 wheels again. I have the wiring harness removed from the firewall to the engine / transmission including the ECM and the underhood electrical fuse box. Next step is to find a complete engine wiring harness from a Lesabre and go from there.