If your 72 750 was built after 3/1972 it may have the 8 rubber 'dowels' around 8 short steel dowels in the inner stud holes.
If built before that, these will not be there.
Either type will work, but if yours doesn't have them now and your new cylinders have them you will have to change your gasket kit to the later type to get the seals. You can probably also buy them separately, but you'll need the little metal dowels, too.