IM LOOKING TO PUT AN ELECTRIC FAN ON MY 2004 HERTIGAGE AND WANT TO KNOW IF IT IS WORTH IT AND WHAT BRAND TO USE. ALSO IF AN UNDERDRIVE PULLY WOULD HELP WITH HP AND MPG? I PUT DAUL EXAUST, K & N FILTER AND AM LOOKING FOR SOME GOOD IDEAS FOR THE 4.2L 5 SPEED. THANKS