Hi Chris, I'm writing from Australia so my suggestions may not totally fit with your situation in the US. I would start by talking to any Engine Rebuild companies around your area. You do not need a Mack specialist but rather an engine rebuilder to see if your old cam can be refurbished. The same companies that grind cams for hot rodders often grind cams for trucks and big marine diesels also. I would defiitely put a new set of lifters in. If one has died the death, there is a good chance the others are on their way out also. Which ever way you go on the camshaft, you are going to need to flush out the oil ways through your engine to get all of the gunge, that was parts of the cam lobe and the lifter, right out of the engine lube galleries. This muck could already be killing your big end and main shells. If you have not pulled the engine right down, when you get it running again, I would be changing the oil and filters every two hours or so maybe four or five times. It will cost you in oil and filters but could save you a block and crankshaft. Hope this helps, Russell Dunn Perth, Western Australia