| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,056 Posts1,055,796 Members48,426 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | The heavy duty option for a 3 speed in a GMC 1955 and up was called a SM320. It was actually a T85 Warner and shares a lot of parts with the Ford version of the T85. Apparently not many GMCs were ordered with the heavy duty option because there are not many of them around. They were a very tough transmission. It is characterized by a 9 bolt shift cover. | | |
|
|
| |
