Auto Racing: CAM & CARB, ford f 250, holley 3310

Question
MR MARZIO.. I HAVE A FORD F-250 3/4 TON 4X4..WITH A 460-4B HOLLEY 600 CARB ..IT DON'T GET ANY FUEL MILAGE AT ALL..I KNOW ITS NOT GOING TO GET REAL GOOD MILAGE ANYWAYS BUT I'M HOPEING BETTER THAN IT GETS NOW..CAN YOU TELL ME WHAT SIZE CAM & CARB THAT WOULD HELP ME ON FUEL MILAGE..THE TRUCK HAS 4.10 GEARS IN REAR END WITH A 4 SPEED TRANS AND
33 INCH TALL TIRES ON 16INCH RIMS..THE TRUCK IS STOCK
THANK YOU VERY MUCH.HAVE A BLESSED DAY
(JIMMY MINCHEW)
MOBILE,ALABAMA

Answer
HI JIMMY.THERE'S A NASTY LITTLE TRICK FORD HAD TO DO TO PASS EMISSIONS TESTS WITH THEIR BIGGEST ENGINE -THEY INSTALLED THE OEM CAMSHAFT WITH RETARDED TIMING ,THIS PRODUCED CLEANER EXHAUST BUT ALSO LOWERED MILEAGE,A HOTTER RUNNING ENGINE AND SLUGGISH LOW END PERFORMANCE ,I'D USE A COMPETITION CAMS #34-225-4 CAMSHAFT (260H GRIND)FOR THE BEST ALL AROUND MILEAGE AND TORQUE ,YOU CAN USE THEIR CAM KIT WITH THE RECOMENDED SPRINGS AND DEFINITELY USE A TOP QUALITY TRUE ROLLER CHAIN (CRANE #35975-1 WOULD BE MY FAVORITE CHOICE,INSTALLED ION THE +2DEGREE SETTING ,SOAK IT IN OIL BEFORE INSTALLING).ANOTHER GREAT PIECE IS AN EDELBROCK PERFORMER (#21660 OR 3766 WITH EGR)MY FAVORITE CARB HERE WOULD BE A HOLLEY #3310-750 VACCUUM CARB.THE STOCK IGNITION CAN BE MODIFIED OR YOU CAN GET A DISTRIBUTOR FROM  DAVIS UNIFIED IGNITION,THE IGNITION CURVE IS MORE IMPORTANT THAN SPARK INTENSITY (ABOUT 18 DEGREES AT IDLE BUILDING TO 35 DEGREES AT 2000 TO 2200 RPM.ADD AN ADJUSTABLE VACCUUM ADVANCE SET FOR AN ADDITIONAL 15 DEGREES BY 3000 RPM FOR LIGHT PEDAL CRUISE).REFILL ALL THE LUBRICANTS WITH SYNTHETIC OILS.( I SAW A 10 HP GAIN ON A WHEEL DYNO FROM THIS WHICH EQUATES TO LESS FRICTION AND A MILEAGE IMPROVEMENT) LASTLY ,GO AFTERR THAT EXHAUST . THE 460 HEAD HAS A BAD TURN RADIUS IN THE EXHAUST PORT SO IT CAN USE ALL OF THE HELP IT CAN GET . HEADERS? OH YES ,HI FLOW CAT CONVERTERS,2 1/2" EXHAUST AND FREE FLOW MUFFLERS .I LIKE DYNO MAX TURBO MUFFLERS -NOT TOO LOUD ,GOOD FLOW ...I HAVE THEM ON MY MALIBU WAGON BRACKET CAR (11.48-114 MPH) .I HOPE THIS HAS BEEN OF SOME HELP ,GOOD LUCK JIM AND LET ME KNOW YOUR RESULTS WHEN YOUR DONE .J MAZIO