Looks like the high rpm misfire was weak factory valvesprings. Bought some new Comp stock replacement 981-16 springs and just replaced the #1 cylinder. Seat load on the old springs was less than 50Lb and open load less than 200Lb! Even had the old brittle stem seals in place. New springs measure about 110 Lb at a height of 1.710" and 280 Lb open, I guess it pays to check spring pressures. Could have resulted in a damaged engine. See the pics below:
Now, I need to do the other seven.
Paul