Thanx 4 all da help, i thought it woz best to go for a 4-1. i didnt know about the hybrid headers, wer can i get one of these from? and how much are they?? i already have a 2 1\4 full mongoose exhaust system and de-cat so ill try the manifold on that b4 i change the exhaust, it all depends on what gains i get. thanx agen 4 da help!