I have a 91 Burb, 350, L480E, 4:10 and 33" tires. It is a bit sluggish when excelerating (off the line or when passing). I'm looking for a performance boost, but living out here in CA, the smog man will shut me down if I do so much as install the wrong color plug wires. Anyone have any experience with performance chips? Is there a noticable difference? Any brand better than others or are they mostly hype? Thanks, Eric M.