230 - 260 horsies depending on the dyno more than anything else. get a professional tune. Fuel economy will slightly improve (but not really that much - your cruising fuel consumption will remain pretty much unaffected and when your on WOT, your using a shittone of fuel anyway.)
i got 230hp with FMIC, 3" turbo back zorst, high flow cat, 12 psi, pod filter & cold air intakes. SAFC2 tuned by matt spry.