THE 3:73 GEARS ARE GOOD CHOICE FOR ALL SETUPS (STREET,TRACK,NITROUS,TURBO,SUPERCHARGED,AND STILL GET DECENT GAS MILEAGE) MY OPINION 3:55'S YOU ARE IN AND OUT OF GEARS TOO MUCH 4:10'S ARE A LITTLE TOO MUCH FOR THE STREET BUT AGAIN JUST MY OPINION. WOULD ALSO USE FORD MOTOR SPORT GEARS THEY ARE A LOT QUIETER THEN RICHMOND OTHER THEN THAT I LIKE 3:73'S