4.0 Sohc Help

Ok, I've done a search on here for SOHC engines the only thing I could come up with where used ones for sell. Haven't seen anything on tech help. I'm looking at purchasing a 97. I got on www.motorcraft.com to see what is interchangeable. It seems only the 97 98 Explorer and 98 mountaineer. Obviously, this wasn't their best design. I'm looking at buying a 97, where the timing chain skipped and needs replaced. The way I understand this is a common problem? There was a grinding so I'm not sure if the valves are bent or if there is any other damage. Has anyone else had this problem on the sohc engine? If so what all was damaged. Also WTF is with parts for the engine. I got on autozone's and oreillys website. They don't sell timing parts for this engine????????????? I'm at the point where I'm thinking of parting out the truck, or maybe I'd be better off selling for as-is $700??

Also I've never seen so much sludge build-up on an engine before. It's like 1/4 inch thick under the timing cover---and I'm not excagerating

Try this site for parts....https://www.rockauto.com/applet3.html