I don't know about a GMC manual. But good luck finding one. And the master parts catalouge will probably be quite helpful, thanks for posting that.

2000 Nissan Frontier, 3.3L (sold)
2006 Chevy Cobalt SS, 2.4L
1952 Chevy 1/2 pickup, 235 c.i. I6
when life speeds up, downshift