Unless the base circle of the cam lobes in question were also worn way down you wouldn't have that kind of gap on both valves in #6 at the same time. I think the valves and guides warmed up towards operating temperature and the valves stuck in the guides.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
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