Workmonster Racing Engines     |   home                      Porting 022 This head is not a maximum effort head by any means, although a set prepared in much the same way, along with a reworked stock manifold,  held an NMCA record in one of the EFI classes for quite awhile way back when. Cost of porting, guides, springs, retainers and valves was about $750 in 1991 dollars.