BS! The rubber on those seals will be hard as rocks, just like a high mileage PCV valve grommet. They will never properly seal once you remove/reinstall the covers. The seals are cheap and easy to replace. My vote is to change them.
I agree. When I removed my front valve cover, those spark plug channel rubber seals were so hard that several of them shattered. One needs a seal puller and it helps to have a seal installer to replace them with a new set. It took a bit of work to remove the old seals as they were really pressed into the valve cover. Don't just buy a new valve cover gasket. Buy the whole valve cover gasket and seal replacement kit and save a trip back to the parts store.
I have already ordered a complete set. Where does one get the 'seal puller and installer?'
You do not need special tools. You have to carefully pry back the retaining tabs with screwdriver and then knock them out with a punch. Make sure you adequately support the VC. I made a press with a carriage bolt and a few large washers but you can drive them in with a hammer and large socket or piece of wood. Again, make sure you supportnthe VC. Observe the depth of the original seals because they do not go all the way in. If you drive them all the way home, you may not have enough engagement with the tubes. Lube them well before installing the VC.
According to the following diagram, the valve covers are attached with shoulder bolts and the pressure exerted by the cover on the gasket is determined by the sandwich of rubber and aluminum washers. This design was to specifically prevent over tightening of the valve cover gasket. So, the correct torque spec is 69 in-lbs but I wouldn't be too concerned with the tolerance on that torque as long as the bolts don't come loose.