I have the same stubborn leak. I used some high quality rtv on the VCs and replaced the copper washers/gaskets on the head bolts, still no luck. Turns out my head actually had a crack in it and was leaking oil from the right side of the head near where the intake rocker shaft goes. Kinda hard to explain but yeah.
I still have a very slight drip from somewhere, I think I just need a new head. It's not too bad now though, So I'll probably just leave it untill I break it. But anyhow...
The method I used to find the leak was removing the crankcase breather hose and GENTLY pressurizing the crankcase with the air hose. I could hear the air hissing out of the crack right away.
If you use too much pressure you could cause other leaks, so with an air gun just give a little blast into the crankcase breather tube and listen for leaks. I soaked my head and jug with soapy water to help pinpoint the leak. I actually just used a little jb weld over the cracked area. Sealed it up pretty good though I still think this head has a crack somewhere. Must have been severly overheated by the previous owner(s).
