yep, about 10 years ago I took a radiator down to a radiator shop in town to get rebuilt. the guy looked at me like I was nuts and sold me a new radiator. then I thought for sure he would want the "core" but didn't want anything to do with it.
not wanting to just throw it away I took it home and its still somewhere in my cluttered garage.
about a year ago or so I replaced a radiator on a 97 grand prix. it took me forever to figure out where the water was going that I was losing, and it would put a little puddle on the ground when parked. I was sure it was a cracked overflow tank so I took that out and leak tested, no leak.
later I found out it was a little bitty crack in one of the plastic tanks on the side of the radiator.
anyway when I got a new one I had hell with those tranny lines, even made a thread here about it. if you don't snug em enough, they leak. if you overtighten, you are screwed. I finally went with some teflon tape.