You better truss the hell out of it as the M20 is widely know as the crappiest diff housing out there, with small tubes and poor quality center sections they love to crack thru the plug weld that retains the axle tube. They also flex so much under moderate wheeling that carrier bearing failures are common.
Yeah the R&P is .375 bigger than a D44 but the housing on the Dana is better IMO.
Scotty you should have no problem hoarding up all the good M20's as I've destroyed 3 of the bad ones!
..... two cracked center sections and a spun bearing on the diff carrier. I went to a narrowed f44/9" and never looked back!
There's been a ton of debate of which is stronger the 9" or D60 , I doubt you will find many people that will take a M20 over ether of them.
You also need to throw in the 8.8 as they've become a popular swap into the CJ/YJ/TJ.
But heck if you can beat your rig and your M20 stays together then go for it!
Jeff