You guys know more about this than I did, (thanks for educating me).
The picture of the T226 has a dirty adapter sitting next to it, what is that for?
That is a PTO extension housing, mounts to the other side (the side you can't see) of T-case in the picture.
Also, since I am a squarebody (1973-1987) aficionado also, GM offered factory/line-built 1 tons beginning in 1977 and used Dana 60s for the front-ends. As 'whateverpratt' says above, NAPCO did GM trucks 1ton and over up through the 70s, and possibly later for the 2 tons and up.
