Ford with a Mopar engine in it

I wouldn't mess with it. A 440 isn't going to be cheaper to build than a 460. And I believe you'll need a new transfer case, the original Ford np205 is a married case with the NP435. If you go 727 you'll need to figure out a transfer case, the 727's had 203's and 208's. Not sure what if any front driveline alignment issues that might cause. The 4wd thing adds a few wrinkles. Haven't tried that combo so maybe there's adaptors or something I don't know about.

The 390 FE in my '71 F100 does great with a pretty mild build, it's coupled to a later '77 np435/np205 which is a strong 4 speed transfer case combo too. I had to make a transfer case mount for that set up in the earlier truck. I've only got 3.50 gears in that truck and it'll still bark and spin the 35" tires starting in 2nd (granny low 1st). My wife killed the original Dana 20 transfer case doing just that. :D