I know this is a stupid question but remember I am new to the classic stang scene. What size of bit, allen, hex or what ever it is do I need to remove the drain plug on a stock 65 rearend?
No need to apologize at all, how else are you going to learn unless you ask questions? Anyway, If I remember right, you can use a 1/2 drive ratchet with an extension and no socket. But unless it's mounted on the bottom, it's a fill plug, not a drain. I do know the '57 wagon 9 inch rear I had in my '65 fastback had a drain plug, but I don't think the stock 8 inch rear did. You can either siphon it with one of those squeeze bulb thingies or if you're removing the gears, it'll come out once you pop the gear case loose.