I have an E21 head that was built by a local M10 race guru. All new components, (rockers, rocker shafts, guides, seals, valves, springs, cam, etc.) It has Isky dual springs, and an Isky 310 regrind. Port, polish, and bench flow by a professional. Head was skimmed a bit but not a ton. All fair offers considered. I can sell w or with out the cam. Email using the link above or call @ (678)850-7311