crossover, no matter how it is done does only one thing, it helps the engine to scavenge the exhaust gasses from the combustion chamber. I have an H on my bronc. Honestly, I can't even tell it is there, but I'm sure a dyno could. There is not enough room to do an X. Unless you are going to be doing Q-mile pulls, the only benefit I have figured, is that it does sound cool with FM's on it(40's). Oh, by the way, I also wrapped my headers to assist in this scavenging effect. I was actually hoping that it would improve fuel milage, but after about 10k miles(30k on engine) I havn't noticed a darn thing. I suppose efi or an egg under the accelerator pedal are the only two ways to achieve that.