the gas we get today is some strange stuff ive seen some very strange things happen to valves a flat valve become cupped a valve burn small and go inside the head i have a 67 283 and use instead of lead my valves are fine all older machines i run lead sub in and i should have run it in some of the newer motors i would have saved some valves the gas is hard on new and old motors they need all the help they can get iv been using gas stablizer it realy works in motors that set around
