Mine is a 4 by and had the 305/70r16's(33's). It put me at 2100 rpms at 70. I avg. 15mpg. I've since gone up 6" with 35's so the 4.10's are now like 3.73. Still much peppier than stock. I also put a t.b. spacer on it when it was stock and raced my buddies identical truck(his was a 99) and would always be ahead by a half truck. Not too bad for $70. Go to randys ring and pinion and play with the calculators,on a 2wd 3.73 would be great.Also check
www.ftw.truckmoxie.com, its an all truck site.