This is exactly what I needed! The measurements I was talking about was the the thickness. It says the 60-77 is .7460-.7470 and 78-up is .7476-.7489 so only a thousandth or so thicker. So I ordered the two lug style part number 12530A, which is listed as 78-up as that's all that available anyways. Only a thousandth difference, worst case it will just tighten my pump clearance by .001.