Not so sure about the P-51 intake I just dropped $1600 for a P-51 and valve covers from Fox Lake. Granted the intake did improve power (no dyno sheet yet). But aside from that it was a very bad experience. Their install instructions suck big time. You have to print them out yourself. They also claim that it fits under a stock hood. It does but it warps the hood on the passenger corner above the headlight. it also puts a mark on top of the intake and inlet tube. You would think that when buying a $1300 intake that you would get decent instructions with it. They also changed the oil fill neck to the drivers side so without looking at the bolt pattern I tried to install the the wrong valve cover. No do***ention whatsoever. If I had known that it was going to be like this I would have never bought from them. Their stuff looks nice and most likely does what it says but it sucks aside from that. Just so I am CLEAR, I am not knocking how their stuff works, I am upset about FALSE ADVERTISING. BOTTOM LINE is they should say that you should get a new hood but you can use the stock one if you dont mind a rub mark and they SHOULD say something about switching the oil filler neck so idiots like me know whats going on from the get go. Talked to Ron at Fox Lake and he said people are cutting holes in thier hood to make it fit and that it is not his problem it is Fords problem because there can be .5" difference in how high the engine mounts. Instead of trying to help he hung up on me. GREAT CUSTOMER SERVICE!!