CNC ported & hand blended to optimze flow. Custom ground camshafts matched to our port programs. Give us your bore size, stroke, rod length, and application. We size critical port areas, choke point and valve seat angles to optimize air velocity specifically for your combination. We use the racing Cosworth Formula for optimizing the cross sectional area to increase port velocity. All heads are CNC machined on Rottler equipment in our in house multi-million dollar CNC machine center, and assembled by specialists with over 60 years in the high performance industry.