318 cam and heads help

Skip what Hughes says.

No machine work, as long as you bench grind .030 off the retainers lock bore...lol

That's the only thing that makes sense for what happened. And thunk about it...the exh lobe is taller and over .500 advertised. Just mock it up and turn the crank by hand , once at full lift, if you don't feel or hea it hit, then just compress the valve at rocker a bit more and see how much clearence there is, you need about .100 to piston.