No, just retard the ignition timing to avoid pinking (which negates any increase made by raising the compression), run Avgas or an Octane booster. It will make a difference but you would be far better off, measuring all of the different gaskets for all of the different models -F/G/J/A/B and seeing if they are any different in thickness and using the thinner one providing it doesnt obstruct the oilways/waterways etc. The gaskets usually use a hollow 'crush ring' in the gasket IIRC and machining this would not give you the desired result.Originally posted by kwakasdave
I know its not by much but if you change the compression will you not have to adjust the opening and closing of valves????????