I shouldn’t be doing math this early in the morning, but I was hoping y’all could clear something up for me. @Mopar1973Man has 3.55 gears and replaced the factory size 265/75/16’s with 245/75/16’s giving him an effective ratio of 3.69. 
 

I have the same 3.55 gears, but from the factory my truck came with 245/75/16’s. If I were to use the tire/gear calculator and switch to 265/75/16 I would have an effective gear ratio of 3.42.

 

So Mike and I have the same gears, but different effective ratio’s based on?? The sticker on the door jamb?

 

From the factory was it 245, with 265 as an option? If so would that mean if you did the 265 option then your effective gear ratio when you rolled of the lot was 3.42?

98.5 to 2002 typically was 265's but when my door sticker was 245/75 R16. Still in all I count from 265's.

My dually is 235/85-16.

1 hour ago, Max Tune said:

My dually is 235/85-16.

With the early version of 215/85 R16 for one tons. Both 215 and 245 are 30 inch tires.