There are later GM gaskets made from I think Neoprene ?? which seal fantastic. Pretty sure they are from Vortec style covers (no bolt holes). They have to be glued to the covers with silicone (I use Ultra Black or Ultra Grey). The ones I used needed to be stretched a little to fit ie. glued one end, allowed to dry then stretched, glued and clamped on the other end. You also have to carefully drill holes for the bolts to pass through.

I was worried they would split by the bolt holes but I have re-used these for years (10+) without a problem, removing the covers many times. Do not silicone them to the head and use the load spreaders on the attaching bolts.

May have one laying around I'll try to get a pic.
Gary

Wouldn't structural adhesive be about the same as using a silicone type of gasket maker/sealant? If you think it'll work better, what are some common brands of the stuff and where can it be picked up? (i.e. building supply store like Home Depot, etc or an auto parts place like Crappy Tire or Napa?) Also, I have enough skinned knuckles from removing rusty bolts so I hope this isn't a crazy glue type of a deal (lol) as I DO wanna be able to remove the covers from time to time without too much hassle. :)

I actually have a Kijiji lead on some cast aluminum valve covers which as a con will ruin the stock look of my engine (what I was going after) but on the pro side will allow me to use a cork seal or hi-temp silicone and the extra stiffness of the aluminum cover sealing area should allow decent tightening of the covers to compress the gasket without distorting the seal area and without leaks. Only problem is they're powder coated black so I'll have to strip and polish them *sigh* but all the extra work is what's so fun about this hobby eh? :)

-- Edited by meowy84 on Monday 16th of September 2013 11:12:36 PM

-- Edited by meowy84 on Monday 16th of September 2013 11:20:58 PM

Structural adhesive  works great