I have done alot of homework and have decided that the Procircuit T4 is the slip on for my raptor. It saves alot of weight, has about a seven horsepower gain, and has optional quiet cores and tuneable tips. I know this seems like I'm a bit of a penny pincher but I just bought a stock raptor headpipe on ebay and removed the heat shields and had it chromed. It looks real good. Now I just need a T4 to slip on to complete the look. The Procircuit head pipe is the same dimensions as stock so I figured why pay 220 bucks for it when I could make my own for just under 120 bucks.
If any one is upgrading from a Procircuit slip on and want to get rid of it please let me know. I'm Looking for a non dented T4 slip on. Thanks.

 

you wont see 7 horsepower gain with the slip-on. The 7 you are referring to is with the full system and airbox mods. I wouldn't get just a slip-on. Ride with what you have until you can afford the full system.