1971-up GM 10 bolts corporate axle

On these axle, is the outside edge (metal edge) of the oil seal round or square?

 

round

 

I have one thats been leaking for some time (more than a year) and have order one (a round one) but when I pulled out the axle, there is a square edge one.....my car is 1970, but im pretty sure its a 8.5...is the 8.2 with round edge too..If I install the round one ,the little round edge make it almost 1/4 shorter than the square one, so the axle will be loose?....

 

i came across these pics in a old manual i got . pain in the a** croping and resizin

 

10 bolt problems

your rear is a 8.2 in 1970 and older. you should be useing the rounded edge part number escapes me but roger knows by heart I am sure...lol seal 2146 is what the part number is with the a9 bearing. try that number or a cross reference of it that should do it. Jim -J D Race