I don't think they are direct "bolt in" replacements. I believe the C/K 10 pickups have a different seat pan that slopes up toward the back of the cab, where the K5 is pretty much just flat. But it couldn't be too hard to fab up a mount to bolt the bench to some K5 seat brackets. But you would loose the folding functionality restricting access to the back seat. I dont think the square body bench seats were"folding" seats. I could be wrong though.