The 74 down seats are the same, bolt pattern wise. The 75 up had the same pattern on the passenger side (I think), but the driver's side was different due to the hump for the catalytic converter, and the inner riser was shorter.
If the floor is solid and hasn't been butchered, there should be four divots in the floor to mark where to drill. The bench seat hump is not used, just plug the holes in it. Also, the factory setup had some extra plates on the rear holes, or maybe the inside holes, to stiffen the floor. Seen many a floor that is cracked and split because those plates were missing.