Bottom line is buy what you like! In this case it sounds like you have a great affection for the '72. Just for your information the 6 cyl will NOT get better fuel mileage than the V8. The V8 doesn't have to work as hard as the 6 to get the truck up to speed. A rough guess would be 10-14 mpg with the 6 and 12-16 with the V8. Others will disagree and some will agree but in the end do what you like.
