With the port profile machined to suit ported heads these are a simple upgrade to maximise airflow in all conditions. The upper flange surface is O-ringed for a perfect seal to either a stock or aftermarket plenum. Fuel injector ports are machined in such a way that either 11mm or 13mm diameter injectors will seat without needing any adaptors, just use the supplied Viton O-rings as required. Fuel rail mounting points are the same as stock, so it is possible to use this with other aftermarket fuel rails.
2004-2006 will require a top feed conversion kit.