Hey guys. I would like your opinions on what upgrade I should do first. Until I get back from my deployment, I only have money for one of these... Volant Powercore CAI with ram air scoop or Hypertech Max Energy programmer. Right now the only mod I've done to my 2001 Suburban 5.3L is just a drop in K&N air filter. Which upgrade would give me the best increase in fuel mileage from where I'm at right now? I've heard that the Volant CAI can increase 2-4 mpg over stock, but I'm already getting 1-2 mpg above stock just with the drop in filter. Thanks in advance for your advice!!!