I have an oil leak around the oil filler tube on the drivers side valve cover. I was wondering if there is a gasket or something in there that failed. Also if I need to take off the valve cover to get to it.

I noticed mine leaking a little before I did my intake gaskets. When I had the valve covers off I cleaned the inside of them the best I could then used brake cleaner to get all the oil out. THe best I could come up with was good ole rtv on the inside around the joint. Hasn't leaked since.

My 1993 350 was showing oil on the rocker (valve) covers. Replacing the breather grommets (one on each cover) was necessary, however you need to remove the rocker covers if you can't pull them out in one piece. Mine had hardened, so I removed the covers and also replaced the rocker gaskets. The grommets and gaskets are sold separately from GM and are worth the cost from the dealer. Total replacement time for me was @ 3-4 hours because of the disconnects for access and clearance.