So I'm thinking of pulling the trigger and buying a D66. I have a 97 F350, Terminator T-500 HPOP, 160CC AC code Alliant injectors, PHP Hydra chip, exhaust, etc. Looking for more power for towing and better fuel economy. Any thoughts on this turbo with what I already have on the truck? Gear ratio is 4.10. Do you thinkI'd get better bang for the buck on the economy side if I re-ratio the truck to 3.73 instead?