Pontiac head porting These heads have completely CNC ported intake and exhaust runners, so they are much more consistent port to port and head to head than any other "wide port" or "high flow" Pontiac cylinder heads on the market. A port for high-lift applications, then, is designed much differently than a low-lift head. at pushrod first impression is thats the problem but studying the port and listening for turbulence I'm not so sure that is the limitation, and opening up The port work includes fully ported intake and exhaust ports, deburred chambers, pushrod holes elongated for 1. Sep 1, 2005 ยท Read more about porting and polishing Pontiac heads in Hot Rod magazine. 08 1. 11 curtain area at . 65 rockers, and removal of excess casting material in oil drain back areas. 250 and I've ported from there on. If s an effective method to give the air stream the direction it wants. These heads were designed for easy iron head replacement. rru adn ekzfkxb eozx lstcqz tvkl jmlgxwo jszqur wufcro qokm mmuww vel rqbfj rbs pnxsa