Thanks autoxcuda! I have been trying to locate some resemblance of a part number on the unit itself, but nothing so far. I have found both cast and stamped numbers, all of which have been 5 digit numbers. Not too many places on this thing that a number could be hidden! At least I can rest assured that I purchased a Detroit Locker, now on to find out if it's in operable shape!

I'm with you on the spool thing. Going in a straight line would be better done with a spool, I would think! I am a drag racing fan, but never been up close with a top fuel or funny car to observe the drivetrain. Kinda wish I could, though.