If you do a juice "without" the attitude on your 03 you will get a little pressure with the rest in duration plus they coax a little timing too all in one box with an in-cab knob. IMO its a nice set up for those with gauges.
As for the VA stack. . try a search, I think I remember it was done back when the duration box first came out, ran pretty hot EGT's with no timing and (2) knobs to turn up.