My sig below is my current setup. I am very curious as to the effects of exchanging my #10 for a #4. The truck is a pretty good performer with the current setup, but I've got the BOMBing bug in a real bad way. My biggest concern is the effects on the transmission. If I'm pushing too much fuel, I can get a bigger turbo. I do not want to blow the trans up. Did that once on the stocker, no way I can afford that again.