How bad are you looking for? How about bent crank shafts with gouged sides or air cooled cylinders with all the fins cut off?
I actually have some of those (don't ask why someone would cut all the fins off, I don't know!)! I am assuming by bad you just mean cylinders that need resleeved or replated, possibly a small weld fix and crank shafts that are likely straight and good, possibly small rust but not rusted completeldy but just have bad rods in them maybe?
Just wanted to clairify b/c some ppl have some really bad stuff laying around!