Olds 455 cubic inch (7.5L) with 3-speed auto (no overdrive).
FWD unit was used at least on Cortez, GMC, and Revcon motorhomes mostly during 1970s.
Alternator capacity can be upgraded easily because original was small by present standards. However, engine was never used on trucks or commercial applications as far as I know, so no factory brackets for a second alternator. Belt drive is being upgraded so there may be a chance to make additional modifications. Trying to rebuild something that old is almost like starting from scratch ó I suppose much like building your own van camper except larger and much more complicated due to old stuff that has to be fixed, replaced, or upgraded. Itís very expensive so hard to justify unless you just want to and can do it.