So I've been looking into getting a bit more performance out of my 01 4.3 4X4 I know I need to replace an o2 sensor and fix my secondary air injection.....I'm gonna start with a full tune up and the tb mod what are some plugs you guys recommend? I've been getting mixed up answers and has anyone got a custom tune? I've seen Nelson, black bear, wheatly and wait4me.....anyone have a custom tune? Just looking for recommendations and ideas. Thanks in advance.