I am swapping out my stock 4.10 gears for a set of 5.13s. i am running 35" pitbull tires which weigh 75 lbs a piece. Truck dynoed in at 504 rwhp and 454 rwtq. I have a fully built 4l70e with billet input and output shafts. was wondering how bad this setup is going to be and if my 5.13s will possibly save my transmission? i have heard horror stories about these things and i got talked into rebuilding it instead of swapping to the 4l80e. I have 100 percent torq management in the trans right now, was wondering if i can pull some out after i do the gear swap and really how much easier is the gears on the Trans?

 

I don't know how far the gear change would help the 4l60e survive, but I can tell you a 4l60 has a hard time surviving under 450-500hp with stock tires.

Nothing will save you at that power level/tire size combo. You have 2 options:
A) 4l80 swap now
B) 4l80 swap later after you spend a lot on the 4l60

It's your call