Doc, From your picture it is a "Eaton" rear(round rear cover) and if stock it is a 5:14 ratio.36 ring gear teeth,7 pinion gear teeth. You should be looking for a third member,Pumpkin/ Gearset from a 1967thru 1972 chevy/GMC 3/4 ton or 1 ton with auto tranny. The gear set will bolt right into your axel housing. It will have 37 ring gear teeth and 9 pinion gear teeth. If you request, I can send a pic of the ring /pinion part number. I have it somewhere in my Pic file. Good luck with your search for this pumpkin. I sold one back in march,2011 for $350.00 plus $130 shipping and have seen them advertised at $450. Jerry.
