So, I was getting a leak from the front valve cover (thank goodness it wasn't the back cover...) and I replaced the gasket. Easy job, not counting the 45 minutes it took to thoroughly clean the gasket track and the mating surface on the head... I torqued it down gently but snug (my son-in-law has my torque wrench... ) and it still leaks! Not as much, but still getting a little oil on the header. I didn't use any gasket goo... So then I torqued it down tightly, which I didn't want to do, given that the valve covers are plastic.. but it still leaks a little. I have another valve cover gasket since I didn't replace the rear one (if it ain't broke etc.). But I've never had a gasket like this--always cork or rubber, not this nylon thing with a track.. is there something I'm missing here?
Other than that this $500 SSEi is coming along nicely. I fixed the water leaks around the doors (just adjusted the doors tighter!) and installed new carpet pad and put the old carpet (cleaned and deodorized) back in. My code with the PRNDL switch didn't pop up again when I tightened the console back down the way it'* supposed to be... It'* amazing how much quiter it is with pad and carpet back in.

Anyway, any thoughts on this valve cover gasket issue?

i just bought valve cover gaskets, and they WERE rubber.. I would get the PERMA DRY, felpro rubber gasket set.. its about a half inch thick, and I can't imagine the gasket leaking.

Mine are blue rubber, part number vs 5008 r

these fit the 93 ssei, your may have a different part nuber. Got mine from NAPA, BTW - you can order just ONE gasket ( different part number ) INSTEAD of buying the complete 2 gasket set.

Just my .02

The valve covers are fiberglass. Torque sequence is as important as torque value.

A random torque sequence is best, stage-torquing (5, then 10 ft/lbs in a random staggered pattern).

If it still leaks, I'd be looking for a cracked valve cover.

Torque specs are in Techinfo (link at the top of the page).

If it still leaks, I'd also be looking at the LIM gaskets, which are common to leak on high-mileage cars where the LIM, Heads, and block meet in the corners.

The LIM gasket is definitely a candidate here. Is there an ultraviolet additive one can add to oil without damaging it and thus pinpoint leaks?

If you have over 100k on the gaskets, just replace them.