I'm preparing to order a 2021 Regular cab, 122"wb and I will be using it to tow a 4500lb travel trailer. I want the 2.7L ecoboost but my dealer says that only comes with the 3.55 axle in that cab config. The 2021 Ford towing guide shows the spec for a Regular cab 122"wb 2.7L with the 3.73...