Dana 60 gear change

You should not have that problem if you have 4.10's. You should already have the right carrier to go to 3.54's. You will only have that problem if those 4.10's turn out to be 4.30's. You will like 3.54 as a street gear. That 440 has more than enough torque to launch an A Body and running on the highway will be a whole new experience. It is also really cool to be able to smoke the tires when you are already cruising at 30 or 40 MPH.