hi,yes i put 3:73 in my 2000 lightning,along with the aluminun drive shaft which is standard on the 2001.Also a level 10 converter and shift kit.The torque is amazing and the gears do make a difference.I also put on 16" wheels and et streets 16x11.5x26 makes your final gear ratio about 4:05 to 4:08.The problem which you may encounter is the input from the computer must be updated,or simply put you must put a chip in to change the gear ratio from the computer which is telling your tranny when to shift.Overall I think you'll enjoy your added power and torque,these trucks are great.Best time to date is a 12.75.good luck