My 70 Challenger has a 9 1/4" rear axle fitted around 1974-78. It has a bad leak on the pinion oil seal. I don't know the exact year or what it came out of. Is there any way to further identify it to get the right seal or are they all the same? Does anybody know the seal part number. I'm in UK so have to order online and would like to get it right first time.