Gearing for 1994 T800 Kenworth

Hello. We are putting a 1994 T800 Kenworth into OTR service. It is currently at 900k miles on original differentials.

The truck was built with 3406B CAT, Eaton RTX14710B 10-speed trans and 4.33 gear ratio in the drives. Of course this truck needs 2000 RPM to get 65 MPH. What is the best solution to get a reasonable cruise RPM at 65-70 mph?

We have 24.5 tires. Thinking to have the rear-end rebuilt (probably needs it anyway at this point?) and have it updated to 3.55?

What about the add-on transmission gear option? Seems there is some type of retro kit for these Eaton transmissions? Our transmission is new (Kenworth rebuild) along with the clutch so thinking not to touch it unless it is the better option.

Thanks in advance!

 

Thank you Brett. It is a .74OD. Looks like we will have to change our rears to 3:55. We were quoted $4500 but seems that's what its going to take.