Budget D100 360 Suggestions

Well, he's retired and on a fixed income, so he really only planned on a re-ring, bearing, and valve job assuming the block and rest of the bottom end checked out ok. I don't mind pitching in where I can with parts if they'd be worth it. I already have electronic ignition stuff, timing set, and a few more odds and ends I'll be able to give him. I'm mainly curious if there's a mild cam that would be an upgrade over stock and still be able to retain the stock rockers.