I have a set of 3.50 gears to trade for the 3.70 gears. If you want to drive over I can swap the gears and posi for you. I have a 65 9 inch for sale. I already have a 67 to 70 9 inch housing so I don't need another.
What I have is not a stock 9 inch rear end. It is an 8 inch converted into a 9 inch by replacing the center part of the housing. A banjo style 9 inch housing is used and this will give you the stock 65 9 inch look. You will be able to use your stock brake set up and axles from your 8 inch as well. Send me a pm if your interested. bob