Leaking valve covers?

[Larry Herman]

Jim, it is usually because the covers warp.  Do not use any kind of silicone seal, as it will squeeze into the motor and strands of silicone seal can plug up oil feed holes to the pistons, etc.

The best thing to use would be Turbo valve covers, as they are thicker and do not easily warp.  You also could try some of the anerobic sealant (not sure of the name) that is used to seal the case halves.  It only hardens under pressure and any excess stays soft and eventually washes away in the oil.