stock comp. 318, which purple shaft is best?

I would call COMPCAMS up directly. If they don't have that cam in stock than they will grind it for you. If you go with the MP cams I would go the 260/268 the other one I would think would be to big for a mild build up. I have run the 260/268 in mildly built 360 and was very pleased with that cam. But like Gotdart said if the heads need to be redone or if the rings are going bad nothing is going to help that motor. Also definately replace that timing gears and chain set, that is allways the first thing I do when I get a Dodge engine. The stock ones are crap!