another j head question

Something else to think about...The surace you have to cut to make the intake fit is the valve cover sealing flange. There is a limit where the valve covers will need to be modified, and they wont have much to seal on. I use .050 as a max there...and just accept that the intake is now dedicated to that engine only. Also, any milling beyond .030 you must check lifter preload and rocker geometry. You will need either shorter pushrods or shims under the rocker shafts.