Just pull the valve cover and check for loose rocker arms on #5. I had a valve stick from to tight of a guide, yours might have been heated enough to swell up and stick. Spray some lube on the stem and see if you can free it up. You sure can't hurt it any more then it is so I say give it a try.
Give those New Old stock gaskets a scrubbing and spray with copper coat before installing, they should work just fine. After all, these are not high winding race motors!
Joe
