thermostat gasket leaking

I don't have an end mill anyway! My aluminum Sixpack intake probably had a pit or two in it, but with sanding and trying different sealers, I was done with it. Never had these issues back in the late sixties and early seventies. I really don't understand it, why some have no issues, others like me do. If you do go o-ring, only torque the bolts to 15-20 inch pounds, that is all it needs. It's about identical to the silicone Real Gasket.