If you don't mind me asking, how do you figure?

 

your in a higher torque band of the motor. when i towed my race car (12klbs all truck trailer and car)with 3.42s it would always downshift out of overdrive.. with the 4.10s i used to have it would rarely do it. havent towed it with the 4.56s yet. but i did put in a set in dozerdans truck, drove to colorado and never downshifted out of overdrive thru the mountains pulling a uhaul.

 

go 4.56 i did and it was the best mod ever. but i also have the 4l80.

 

and the 4.56 are strong my trans shifts hard and cherps 2nd and 3rd the grears are holding up fine. if i havent broke them yet they will hold up.

 

Hmmm gotcha. See i have to go to 5.13's to be equal to a 4.56 with my 33" mud tires. might be although. But was planning on just 4.88's which is equal to a 4.30

 

i ended up buying a 4.10 front diff out of a wrecked truck, and gonna put a set of motive or yukon 4.10's in the rear.