I think I would adertise on the buy/sell of this forum and buy a matching pair of heads, 54 or 55. Considering the labor, go ahead and put your money in heads that have not been cracked, and a complete valve job with new guides and hardened seats to run on modern unleaded fuels. Do it right, and youll soon forget the money spent, do it wrong and youll be doing it all again. I believe most guys on this forum are honest, but if sellers dont know the factual conditon of the heads they are selling, go ahead and pay for cleaning & magnaflux. They might even split it with you. Good luck, Ill dig around my area to see if I can turn up anything.