These are the TFS Ford High Port 225cc intake runner aluminum heads with 58cc chambers, Titanium Retainers. Looking for serious horsepower? Trick Flow® High Port® 225 cylinder heads are specifically designed for large cubic inch small block Ford engines, as well as engines with high-boost superchargers or turbos, big shot nitrous oxide systems, and other mega-power combinations. They feature unique valve spacing. Raised exhaust runners, extra-strong castings, and thick decks for additional rigidity and gasket integrity, superior cooling characteristics, and, most importantly, excellent airflow. Trick Flow® High Port® 225 heads have top-of-the-line CNC Competition Ported runners with a high-resolution surface finish for maximum airflow and power over the entire rpm…