So i just pulled my valve covers off tonight, first time since i have had the car for over 23 years........actually i started a project working on the injectors, then thought why dont i work on them covers, while i got everything apart. They are getting quite crappy looking, and thus need a good cleaning. So now i am thinking to replace the cover gaskets while i am at. Any recommended gaskets? I read some other posts, it appears that GM could have used a rubber silicone from the factory? The stock gaskets look real good, seemed to be sealing well. Just a little oil in the middle of the gasket, lower edge on both sides. 1988 IROC 350 TPI

The rubber type gaskets used on the center bolt covers seal very well compared to the old cork gaskets. Just due to age, if you already have the covers off replace them with soft new ones. Fel-Pro does good quality gaskets and they are inexpensive.

Sounds good. I like the soft rubber style. I just looked on AA website, lots of choices, but the soft rubber Felpro versions were in stock!

Check out this picture of the bottoms of the covers....
Not bad for being original, over 27 years old.....!

Changed them out over the weekend. Went with the Felpro blue rubber gaskets, they were only 20$. did not use any glues or silicones on either side. They were a stretch fit, and seemed to hold in the lip of the cover. Drivers side went down easy, but the pass side was a little trickey, lots of crap in the way.
Now just gotta get my injectors back, and i can start putting the TPI all back togethor!

Pretty good, I was very surprised how good my valve train looked when I changed the gaskets on mine. Driver side was easy but getting the passenger side valve cover to seal was a royal PITA, it's still not completely sealed but the leak is so minimal that I got over it. Since your TPI system is taken apart it was probably easier for you to get a good seal. I spent many hours in the hot Florida sun cursing at it last year

Interesting.....wonder why that side wouldnt seal? torque the center bolts down good? i like the design, gasket sets in a valley inside the cover. mates up to the head, which has a raised edge just small enough to fit in the gasket area.....with the center bolts i think they are easier than the old school covers.

My valve covers have perimeter bolts not center and I snugged them down enough to hold but not enough to over tighten, I got steel covers so they wouldn't warp and bend as well, I think my problem was that the valve covers are taller than the stock ones so the a.i.r tubing coming off the manifolds was pushing on the cover, I tried every trick in the book from this site to get them to seal, had them sealed pretty good and then a month later decided to sea foam my car and after that a small leak started .