It depends on a lot of variables, What do you mean by speed? Acceleration? Or top speed? Stock tires? About a hundred other things to consider. If you want to stick with stock tires, and you want to race from stop light to stop light 4:10's are good. You Probably are going to have to hold back to keep from spinning though. I am guessing 235/75/15's for tires with that small of gearing from the factory.

 

A stock 2003 dodge ram with a Hemi and 4WD and Quad cab runs an average of 7.0 seconds 0-60 time and low 15's at 89 MPH in the quarter mile.

The ranger 4x4 ext cab auto with a 4.0 and 4:10's is a low 8 sec. 0-60 car with about a 16 sec. quarter mile at about 86 on average reviews. 0-60 times are a ways apart, but the quarter mile times are closer. This is normal for ford with their OHC motors.

~HJ