I looked at a 53MY 1972 a few years back that was delivered new with VT8-370M's. Those motors were "fine" for that application, but they were no better than 8v71n's. It is much easier to find parts and service for the old Detroits than it is for those old Cummins. I would not swap them. You can probably find some 8v71 take outs if you don't want to rebuild what you have.