High Compression Head, aluminum. For use with modern style 14mm spark plugs and high radiators. Ford Script head has complete original appearance when installed. "Z" style combustion chamber. 6 to 1 compression ratio, extra water capacity for better cooling and adds approximately 7 HP. No modifications to your engine are required. Uses standard Model T head gasket. Use with stock style pistons, this head cannot be used with high compression pistons. (uses part# 3001MBH to mount to head, sold separately). Note: Low style heads are 2" tall and high heads are 2.5" tall. This is the measurement from the head gasket surface to under the head of the head bolt.