i called k&n about the difference in the 63 model 57 model and they could not tell me. my buddie has the 63 on his 08 and i am thinking of buying it and putting it on my 05 and the 05 calls for the 57 i was wondering if someone could help me and let me know if the 63 series would fit on my 05 f150 they are both the 5.4 and also both are FX4 packages. please i need to know before i buy this thanks

 

If it fits, and there is no visible difference, then go for it. I don't see any problems with it. Probably just different numbers for different years. Hell, I know guys that build thier own CAI systems. lol