I replaced the intake on my wife's 03 5.4 Expedition and found out someone replaced the intake at some point to a Dorman. We bought the truck with 118K miles on it so I have no idea of when it was replaced. About 9 months ago it was at around 134K miles and it began to leak from the front by the crossover so I assumed it was cracked. It turns out the gaskets were trashed because I found no cracks or breaks upon inspection. I bought a new Ford OEM intake to replace it and fixed all the misfiring coils and new plugs while doing this job. After buttoning everything up and test driving it, I then discovered the catalytic converters were ruined from driving it with misfires so long. So I replaced the assembly with the Magnaflow Hi flow 4 cat assembly and a straight through Magnaflow muffler. Well my point is I don't know how restrictive the Dorman intake was, because I upgraded the exhaust at the same time as replacing the intake, but the truck has way more torque than ever and pulls harder up top too. I know for sure 4.6 Dorman intakes for PI cars are restrictive because they use NPI runners with PI flanges and it kills the mid to high end power. My point is buy OEM if possible and skip the reliability and power issues associated with the Dorman intake. Also if anyone think the intakes are ok and wants the Dorman intake you can have it if you pay for shipping. I didn't want to just throw it away. If it turns out to have a leak I will return your cost for shipping because I am a person of integrity and absolutely couldn't find anything wrong with it. Message me if interested.