Re: Best flowing Factory Head
Stock AU head has the largest valves, smallest valve stem diameter and flows 300hp so it should be the go but it has small ports and a nasty bulge between the valves so it can defintely be improved. EF have smaller ex valves but bigger ports. Either way both are fine for porting. If you want to bolt on a stock head the AU will be best but you need the rocker gear and cam to suit.
AUII Auto wagon 4.0L InTech Pacemaker PH4480 extractors, 2.5" exhaust, JMM DEV3HL Cam Unichip 144rwkw. 1/4 mile email@example.com