An FYI, this is a slow lumpy starting motor. That part 'sounds normal'. I just looked it up and 84-108 Pounds / Square Inch is what it should be. You are in fact reading running compression, not cranking. I'd bet the compression release has broke. If valve timing was off you should have seen a drop in compression. Running full compression on start will get you all kinds of pre ignition problems, way to much compression way to early in the stroke, popping through the intake. Yep, get that valve cover off. Focus on the compression release. I don't know if it's a serviceable part or if you're going to need to source an exhaust cam. Lots of parts shown for the exhaust cam, two pins, two interlocked shafts, the cam itself. Sheesh. Let us know.