CYCO shoes! Last seemingly forever! I have replaced hundreds of shoes, but never replaced CYCO, never needed to. They make HD replacement gaskets, good stuff too! My bikes, and a lot of my customers run cams in the high .550 lifts to over .630 lifts, and never replaced CYCO shoes. ALSO, you buy shoes from HD and you get the entire overpriced tensioner assys. Over $100.00 each (there are 2 in there), but CYCO, you buy the 2 shoes and replacement pin/rivets for about $20.00.
They do not come with instructions, it's a pretty easy deal, but I recommend taking a pic of each before disassembly so you get the shoe orientation correct. You have to grind the old rivet head off with a bench grinder or Drexel tool, and lightly peen over the new rivet head. Don't get carried away peening over the head,, it doesn't take much. Too much, and the shoe will bind up. Also, when installing the new rivets, install them with the head AWAY from the cam plate. There is only a small amount of peening required to keep the rivets from falling out, but if the head is installed towards the cam plate, it usually rubs against the plate, and you will get a bit of aluminum scratched off. It USUALLY causes no problems, but why take the chance.
You won't find these shoes at dealers, only indies. CYCO makes automotive cam chain replacement tensioners and gaskets too, so they know what they are doing!