I'll probably be throwed off of this list,(lol) for saying this, but, you can, if you're real desperate, get one through Advance Auto Parts, if you have one in your area? And, I'm sure other parts houses as well. About 3 or 4 years ago, mine went on the fritz and Advance quoted $199 for a rebuilt one, with exchange. You probably already know this, but it must be for a 4WD. The 2 WD looks identical and will fit right on, BUT, it turns opposite of the 4WD. At this point I might also add that mine is a 76 with the box on the outside of the frame, while yours is located on the inside of the frame. So, you may be able to use a 2WD, but just be sure to check for proper rotation. Hope this helps.
Thanks,
John