Head gasket recommendations for magnum

I got confused, thought you were asking about how I got the measurement for lift but I did the clay thing, put the head on the block, put the rocker arms on the cylinder I was checking clearence for, rotated the engine while looking at the exhaust valve opening via looking at the rocker arm opening the valve and the engine stop rotating so I assumed it hit the exhaust valve so rotated the other way for the intake to open and felt a very slight stop while rotating the engine, did kept going to where the exhaust was starting to open and when it got close to high lift it stopped against assumed the exhaust valve is hitting. Took the head off and clay was smashed to where I couldn’t read it and I did mention I didn’t degree the cam but advanced it 4 degree advanced on the crank