I have a regular head for a 235, not a 848,I have decided to have it milled and to sink the intake valves as some have suggested.I am not sure if I should have larger intake valves put in ,or just keep the ones I have.Would there be much gain by going to larger valve?I know That this engine won't make much HP,but would like a little increase if I can get a little.In a few years ,I plan to go to a 250,or 292.