There were several other changes to the 7,8, and 9 when the Cummins engine went in with the G series. The basic layout is the same, but things moved around in places. A winch from an earlier series won't bolt onto a G or later.
Cummins does have the B3.3, 3.3L 4 cylinder, that I guess is considerably smaller than the 3.9L, some guys swap it into Jeeps and such. If you look close, you may find that's what's in there.