rather than mill a head that far, that you would have not enough threads left on the intake side is foolish. you would do better to get a better piston for the job. do it right or don't do it! Al
Bingo. Once asked the question to shave a big chamber J head enough to make compression on a 318 i decided to go with really tall 318 pistons and shave just enough to clean up the deck face on the head. Wild.