wEBER 34/36 OR 38?

I AM LOOKING FOR DEACENT PERFORMANCE OUT OF MY 86 B2000 W/A 2200 MOTOR I STILL NEED TO GET GOOD GAS MILEAGE OUT OF IT SINCE IT SEES 90% HIGHWAY. AS FAR AS THE 38 GOES HOW MUCH "DETUNING DOES IT REQUIRE ? ALSO I WILL BE PUTTING ON A HEADER AND EXHAUST...ANY HELP WOULD BE APRICIATED SINCE I AM A FORME S-10 GUY AND AFTER BUYING MY BROTHERS MAZDA I AM IN LOVE BUT THIS IMPORT THING IS STILL NEEW TO ME THANKS
NATHAN

CHECK OUT THIS POST FROM A COUPLE OF DAYS AGO

I'D SAY IF ALL YOUR GOING TO DO IS HEADER & FULL EXHAUST POSSIBLY AN IGNITION UPGRADE THEN THE NEW 34 WOULD GIVE YOU THE FUEL ECONOMY + STILL HAVE SOME AMOUNT OF PERFORMANCE

mazda and performance do not go together but the 32/36 is what you want the 38 just uses more gas