If it were me, I would pull the valve covers, then I would pull an intake bolt, one at a time, and use a NON hardening thread sealant and re-install and torque to spec. Telfon tape would probably work, but in my mind it would be possible for little shreds to fall into the oil path and get pushed through the system.
Then just for giggles, I would "fit" the valve covers. To do this, place them on the head WITHOUT a gasket and make sure they are sitting firmly on the head rail. IF they are not, mark the spot where it possibly is hitting the intakerunner, use a Dremel if you have one and remove just a little material at a time until the covers sit firmly on the head, install the gaskets and bolts and torque to spec.