Just for reference, I hit this problem also. It's not obvious (at least not to me) - it looks like it seals, but I get leaks at RPM and when I'm up to temperature (thinner oil) - I'll pull the cover and grind tomorrow. Torquing down the valve cover does not increase the pressure on the seal, so I know something is out of wack. I've used ARPs before and this is the first time I've had an issue. Block was cleaned (tanked), threads were tapped, and the bolt holes sprayed out while upside down.

22REturbo.net




1988 4Runner
22RTE core, turbocharged, megasquirted...