I;ve got a 96' 4.0 Pushrod V6 Explorer, and was wondering if there were any free mods I could do to it. I already have a drop in K and N air filter, and ran a 10.7 in the 1/8th, but I think I could do better. Also, I was thinking of headers, but was wondering how much of a difference they would be, and what brand, and how hard would it be to install them. Thanks.