I just pulled the rear end out of my truck and am trying to find out what it actually is. so far I have found out that it's out of a 68 or 69 Camaro. It's a posi with a 4:88 gears (think it was originally a 3:55) The numbers are as follows: On the housing 3894860NF, on the axle tube BT 050507 C2 and on the GM ring gear 3862528 8 39 4 70. These are all the numbers I can find. If anyone can help I would really appreciate it.

 

Post up in the 1st gen section and I'm sure someone will be able to help you out.