ProMAXX Shocker CNC Series is the top of the line performance cylinder head. It features professionally designed runners and chambers that are meticulously CNC ported. The all new ProMAXX ultra smooth Grade A 356-T6 aluminum casting is CNC machined to create the perfect platform for newly developed runner and chamber designs. This is combined with a 5 angle competition valve job, diamond honed bronze guides, large spring pockets and professional assembly, performed right here in the United States. Pro MAXX Shocker CNC Heads are proof that going fast doesn’t have to break the bank.