Nice 80, dont see a lot of them
I'd go with the van 360. Does it have a trans? You should be able to use either a 904 or 727 in the F. Same trans x-member for all. The wagon probably has an 8-1/4 and HD rear brakes w/finned drums. Both of the wagons I had did. The bent t-bars leave a lot of choices for exhaust manifolds.