While the TC's and Evo's are totally different engines, the technology between the base gaskets and head gaskets is not. I've done several of both now.
They do change the heads on the Road Kings as well. I was just chatting on Saturday with the SM about the whole ordeal and he indicated he had several RK sets with nothing wrong that he could tell. He wanted to be able to play witha set or 2, but can't due to the whole warranty issue.
While I indicated that I'd had gaskets done several times, I've also had the heads replaced, cylinders replaced, base gaskets done several times, head gaskets done several times and rocker boxes clearanced. Whatever they can get the moco to agree to, that's what's been done.
Too thin an area for the gasket to seat on, lots of heat due to EPA mandated lean running, etc, etc. It's what we bought. Just like the Evo, there were problems with those too. There were more than a few that had base gasket problems.