[Walt Fricke]

As you may have noticed, there are some accomplished engine builders who swear by the Vitons, and at the blue ones.

Not knowing any better, I have used the blue ones. Yes, they tear some even if you are careful to hold the bolt end when tightening. My main gripe is that this means only one out of 20 or so can be reused, and I am cheap and like to reuse things. I bought a largish (for a home brewer) amount of the blues a while back, before being educated (or confused) by this fine forum's contributors.

But my engines have not leaked here. Other places (the chain box to case seal is my bete noire, and RSR rings don't seem to keep the rocker shafts from weeping) do, naturally, a bit.

I'd be more concerned, as you are, about getting a critical and permanent clamping force than I would about the disadvantages of blue seals. For this reason I gave up using the CV joint gaskets - I think often the initial torque is not enough to get enough CV metal to hub metal clamping. But those you can easily retorque after running. Not so for the case bolts.

But if you are patient, perhaps Steve or Henry or one of the other guys who do lots and lots of engines can opine. A washer gap would freak me out, too.