Flat top pistons in Ford Modular Motors will generally provide compression ratios in the 9.0 to 10.5:1 range. which makes them a good option for engines utilizing power adders and larger than stock camshafts. Valve reliefs are configured to work with most types of standard and aluminum cylinder heads and will normally fit most high performance camshafts. Pistons for 2V - 3V and 4V are included.