i asked this question on oldgmctrucks.com and i have been told to install it in the "down" position. I checked out my old ones and found the spot where the nut had worn down the metal and determined they were installed in the "down" position. I also looked at my pictures of the truck before i took it all apart and that was the same thing i found out. I think this allows for the full range of motion of the shock absorber, but i'm not completely sure. i am fairly sure that i have them correct in the "down" position.
