Gary, what Tim shows is good info for the OE pair of bushings and seal in the torque tube. The seal may fail due to age or due to wear of the bushings (which allows the driveshaft to wobble) or both.
There is an alternative fix, referred to as an Okie bushing (as mentioned by Carl), that was developed in the '40's which makes somewhat easier the bushing and seal replacement, without the need to remove the driveshaft. Several vendors carry them, such as this: Okie Bushing
. Scroll down to the Instructions tab to get to the diagram and installation guidance. They also sell a tool that may be used to pull the forward OE bushing, although the tool has received very mixed reviews on the forum.
More important, there are 3 sizes of the Okie bushings being reproduced, AFAIK. Chev's of the 40's has the ODs listed. Make sure you get the correct one by the dimensions (there have been people in various forums who had issues after receiving the wrong size bushing assembly, or bad repro's made in India that were slightly off in dimension).
Here's a great post in the forum that shows better photos and diagrams: Okie Bushing Install
. Search a bit and you will find more info.
The Okie Bushing is so called since it was developed and patented in '46 by National Machine Works of Oklahoma. Note you will frequently find it misspelled as Oakie Bushing
(as Chev's of the 40's does). Just for fun, here's the original patent: 1946 Okie Bushing Patent # 2,403,520
So, you have your choice - the Okie Bushing, or replace with OE style bushings and seal. Good luck!