on my 1987 comanche i just did a pace setter headerback exhaust with dummy cat and super 44 flowmaster and 2 1/2" piping it sounds great but i would never recomend anyone to buy these headers just because they are a pain to install i had to dent in header 1 and 4 to get the intake manifold to set on flush and its very hard to get to bolt number 2 to tighten. i have put borla headers on 4.0 motors and they are so much easier its almost like your paying the xtra money for them to fit right. well i pulled a couple of my spark plugs and it looks like its running lean, it also has a little bit of heasitation when i just step on the gas. so i was wondering it their is any way i can get a little more fuel in it? without making it run too rich i seen some people on here tried mustang injectors but i didnt realy get a straight answer about how they perform with just headerback exhaust anyone got any sugestions?