Hi all ,New guy here with a puzzel .I have recently picked up a rear diff from a guy for free he told me it was out of a 61 merc but thats all he new.Can someone tell me what it is .I was told it may be a 9inch posi.these are the numbers i could find..center secion c7aw-4025c on the pinnion support 3j18---c2aw-4668 on outside of center section 3h15.There is a drain plug on the assembly and no visable hump and 2 dimples. there is numbers on the ring gear. 6-468 shift2. c2aw-42103 also below center section bearing cap on insider there is 4224. Please what the heck is it. TONY