Well, after doing some research on past forums, the manual, and parts catalogs, I believe I have a handle on the situation.
First, I should have named this thread "Light Duty AD Cabs vs the AD Big Bolts", since the year of the AD Cab is not the issue. As Tim pointed out, the bigger trucks used a hand lever assembly whereas the lighter trucks utilized a foot actuated assembly.
What really brought it all together was a thread that occurred about a week ago and Dads50 Photobucket Account, pic #124. The difference is a bracket that attaches to the firewall. As Dads50 pointed out, the bracket attaches to the firewall and the inner fender attaches to the bracket. The parking brake lock bar goes through the toe pan and the foot lever goes through the cab floor and attaches to a cross assembly.
I'll email you about the transmission cover,GMCPic.
Thanks for the interest.
