The stock head needs help for performance use. Gregg Hansen of Stage VEngineering spent an afternoon relieving the bowl areas, enlarging theports, and gasket matching. Then, Gene Ohly milled 0.100 off the deck,reducing chamber volume from 54 cc to 44 cc, bumping compression to9.2:1 with the stock-replacement flat-top pistons. He also installedoversize hardened seats and bronze valve guides and performed athree-angle valve job. If you're building an aluminum block, tell yourhead porter not to back-cut the chamber walls adjacent to the valveheads to unshroud them. Doing so reduces the area available to pinch thehead gasket's fire ring and can lead to chronic gasket failure. Our headwas unshrouded slightly (note the 8 and 2 o'clock positions), but we gotaway with it.