I'm also a big fan of early OD's. In addition, later Saganaw 3sp OD's and T5's are a good way to go. However, you need to do a cost comparison between doing the rear end and switching to an OD.
Any transmission change will require a driveshaft modification for your particular truck.
3 Speed OD's will require either the column shift linkage or a modified floor shift set up. You will also need the electrical components.
T5's have issues as well such as location of the shift tower, clutch replacement, and some of the later units are designed for electric speedometers.
All of the above can be overcome but they are things to consider.
Fred
