Cyl sidewall wear with a 416

Judging from the lifter wear, the story you got on the engine is probably spot on. Also, without pictures, the cylinder wear is tough to comment on. Most any build you can rock the pistons around in the bore on. I wouldn't sweat that. Often times if an engine is overheated, that can translate into premature piston/cylinder wear. But, without pictures, it's a tough call.