67 W200 Which motor would you use?

I just bought a 1967 W200 camper special 2wd. It has a 383 with a 727 tranny in it now. It is all original with 46600 miles on it. I have a 1974 440 out of a motorhome that I was thinking of rebuilding to put in it. What would everyone else do? Rebuild the 383 and keep it numbers matching or go with the 440?