The most accurate axle/model chart to date. To get your axle ratio from the model code, look at your tag on the inside of your door jam. You will see a 10 digit alphanumeric code. The code will start with VZ if you have a V6, and RZ if you have the 2.7L. It seems the tire size listed on the inside of the door jam is irrelevant as many people's trucks come with 31" or 265's from the factory but have the 225 size listed on the door. Just go with the tires your truck came with from the dealer unless you know for a fact the tires/rims were changed by you or the dealer.

RZN140L-TRMDKAB	3.416
RZN140L-TRMDKAB	3.583 2001-2002
RZN140L-TRPDKAB	3.727 2001-2002
RZN140L-TRSDKAB	3.583
RZN150L-CRMDKAB	3.416
RZN150L-CRMDKAB	3.583 2001-2002
RZN150L-CRPDKAB	3.727 2001-2002
RZN150L-CRSDKAB	3.583
RZN161L-TRMDKAB	3.583
RZN161L-TRMDKAB	4.100 With 10.5R 15 Tire, 7JJ Wheel 1997-98
RZN161L-TRMDKAB	4.100 With 31x10.5R 15 or P265/75R 15 tire 1999
RZN161L-TRMDKAB	3.909 2000
RZN161L-TRMDKAB	4.300 With 31x10.5R 15 or P265/75R 15 tire 2000
RZN161L-TRPDKAB	4.100
RZN161L-TRPDKAB	4.555 With 10.5R 15 Tire, 7JJ Wheel 1997-98
RZN161L-TRPDKAB	4.555 With 31x10.5R 15 or P265/75R 15 tire 1999-2002
RZN171L-CRMDKAB	3.583 1997-1999
RZN171L-CRMDKAB	4.100 With 10.5R 15 Tire, 7JJ Wheel 1997-98
RZN171L-CRMDKAB	4.100 With 31x10.5R 15 or P265/75R 15 tire 1999
RZN171L-CRMDKAB	3.909 2000-2002
RZN171L-CRMDKAB	4.300 With 31x10.5R 15 or P265/75R 15 tire 2000-2002
RZN171L-CRPDKAB	4.100
RZN171L-CRPDKAB	4.555 With 10.5R 15 Tire, 7JJ Wheel 1997-98
RZN171L-CRPDKAB	4.555 With 31x10.5R 15 or P265/75R 15 tire 1999-2002
RZN191L-TRPDKAB	3.909
RZN191L-TRPDKAB	4.300 With 31x10.5R 15 or P265/75R15 or P265/70R16 tire
RZN196L-CRPDKAB	3.909
RZN196L-CRPDKAB	4.300 With 31x10.5R 15 or P265/75R15 tire
RZN196L-CRPDKAB	4.100
RZN196L-CRPDKAB	4.555 With 31x10.5R 15 or P265/75R 15 or P265/70R16 tire
RZN196L-PRPDKAB	4.100
RZN196L-PRPDKAB	4.555 With P265/70R16 tire
VZN150L-CRMDKAB	3.153
VZN150L-CRSDKAB	3.153 1997-98 & 2000, 3.583 1999
VZN150L-CRSDKAB	4.100 With 31x10.5R 15 or P265/75R 15 tire
VZN160L-TRMDKAB	3.909
VZN160L-TRPDKAB	4.100 With 10.5R 15 Tire, 7JJ Wheel
VZN170L-CRMDKAB	3.909
VZN170L-CRMDKAB	4.100 With 10.5R 15 Tire, 7JJ Wheel
VZN170L-CRMGKAB	3.909
VZN170L-CRMGKAB	4.100 With 10.5R 15 Tire, 7JJ Wheel
VZN170L-CRPDKAB	3.909
VZN170L-CRPDKAB	4.100 With 10.5R 15 Tire, 7JJ Wheel, or P265/70R 16 tire
VZN170L-CRPGKAB	3.909
VZN170L-CRPGKAB	4.100 With 10.5R 15 Tire, 7JJ Wheel
VZN170L-PRPDKAB	3.909
VZN170L-PRPDKAB	4.10 w/ P265/70R 16 tire
VZN195L-CRPDKAB	3.909
VZN195L-CRPDKAB	4.100 With 31x10.5R 15 or P235/55R16 tire