That approach is like taking aspirin for the headache caused by a brain tumor. It might relieve the symptoms temporarily, but it does nothing to solve the underlying problem. Shimming the head up with two gaskets will prevent a piston/valve crash and burn, but it will do nothing to resolve the valve edge erosion caused by exposing the valve to the flame front travel that happens 60 times a second at 2K RPM. If the fuel mix is slightly lean, that flame temperature can approach 2,000 degrees F. That's hotter than some parts of an acetylene torch flame.
Jerry
