I looked underneith to see what would be involved with replacing the rear shocks on me '77 K5 and it apears the bolt on the top of the shock can only be accessed by removing the gas tank. The shock is mounted to the frame rail with a through bolt with a flat head on the outside of the framerail and a nut on the inside that I could barely touch with my fingers sqeezed up between the inside of the frame rail and the gas tank. Its like this on both shocks....I know they didn't make it so you have to remove the gas tank to replace the rear shocks did they?