Just to back up Jerry's length info, a search through my older GMC Books of Parts (1940-46) shows all the GMC engines (up through the 302) used the same GM# 2135418 connecting rod. Using that info, I looked in the earlier GMC Shop Manuals I have (1940-45) and they show the stock length specifications as 6.998" - 7.003".
All my references after the 1945 Shop Manual stopped listing the rod length. It only listed large and small end dimensions and bearing/bushing info. Guess maybe they figured you didn't have to keep restating what hasn't changed.
