Silicone VS standard Valve cover gaskets

[mrclubike]

Just a update on having my heads rebuilt by Ted Porter

Ted recommended having the valve cover mating surfaces milled parallel to the head gasket surface
It was $60.00 USD extra
And I got new valve covers 
It was worth it
I no longer have to use the silicone valve cover gasket to get them to seal up
I now use standard valve cover gaskets

Standard gaskets seal just fine when everything is flat
The Valve Cover  nuts now tighten up well instead of the loose feel you get with the silicone
I have had the valve covers off at least 4 times with the same gaskets and they seal up just fine

The heads are performing very well 
 

[Barry]

Sounds like a good result. Standard gaskets last near for ever after dozens of cover removals.

[nhmaf]

The silicone ones have been very helpful for me with my R100/7 heads that seem to do a slight drip or two no matter what I did with the standard valve cover gaskets on there.  I don't have the cash on hand now to re-mill them, so the gummy-bear material is welcome... but I agree, I prefer the positive feel and performance of the standard gaskets when things are flat & true...  at least my R65LS is in good shape this way.

[Justin B.]

Although I have a mill I've never used it to true up valve covers.  I just put a sheet of sandpaper on glass and "lap" the gasket surface using a figure-eight pattern.