I just recently bought a used C-8 off of a very large 6 wheel dump truck. ( bigger than the one ton variety). The mounts he had were different than mine. But I bought new frame mount bracket and the lift frame for my 95 k2500. Went on with no problem and the truck holds the plow just fine. Nothing scrapes and plow itself is fine. I don't know if that answers your question, but I hope it helped.
With any plow the idea is to have the A-frame parallel to the ground. Of course as a cutting edge wears this height will change slightly but that is what you should base it on. If the plow cme off the same type truck it should fit fine as long as neither was lifted. If in doubt go to a good Meyer dealer. They should have books with the mounting specs in them.