Yep, you need to change your v'cover gaskets for sure. If it is only in the front bank, then you can tighten the cover down a little to buy yourself a little more time. Just a little though as these bolts have been known to snap if you torque em to much. If the rear has leaks, well time to replace it. The front is simple, take the v'cover off and replace the gasket. The rear is more involved as you have to take off the intake, disconnect vacuum lines and have to replace the intake gasket. Here is your homework assignment, search phenolic spacers in this forum and valve cover gaskets, you should get lot of good reading material.