Your 66 w/273 should have a 22 in radiator with the lower hose on the driver’s side; the one with the slant should have a 19 in with the upper and lower hose connections in the wrong locations. The Aspen could have a 22 in radiator but more likely a 26 in and likely to have the lower hose connection on the passenger side. You could use the Aspen by drilling new mounting Holes in the core support, relocating the lower hose connection or swapping 70-up water pumps as a start. Why not get yours recored?