chips are designed best for standard intake and exhaust mods, thus work better if you have these mods. though you'll still see gains with just a chip. if you do many, many mods, then a custom burned chip will account for all of them, though it cost mucho $$$ for the dyno time, o2 and a/f readings + custom programming fee. and here is levloc atx shifter for $80:
levloc 
