truck is in my sig. Right now it has 3:55 and with my 5.0 and 33" tires it certainly doesn't have crazy off the line power. Don't get me wrong it isn't a dog because of some minor upgrades but I want better off the line power. Is changing the ratios something I could easily do myself?
EASIEST way??? Find a good axle from a donor truck with the ratio you want, it's a unbolt/bolt in operation. Now, one of the other guys here, will have to explain how to set up the speed sensor etc if it has one.
Setting up the Ring and Pinion in YOUR axle, requires some special know how, I'ds not do it myself.
I found a front diff with 4.10's, but the PO put them in. I think I'm going to have to redo it as well. But, for $100 for the diff and an entire rear axle I can't complain. Keep an eye out. They are out there, you just have to look.
It is not rocket science to install gears but it does require some special tools and knowledge. Trying to explain it over the web is futile at best. It is not for the average do-it-yourselfer. You could try to find axles from a F250 but then you would have to use 8-lug wheels.
Personally I do not think a swap from 3.55 to 4.10 (that is the shortest gear you will likely find in a donor) is going to do much for you. That 5.0L needs gears to get moving. The larger the tire, the shorter the gear you need. I have recommended 4.56s to you and others with similar combos before. When it comes to gears go big or go home.
Hey, I never promised you a Rose Garden! LOL!
Installing a R & P requires setting up proper lash etc, if you get it either too much, or too little, you'll eat them up fast. Find someone who knows his stuff, and let him set the pinion depth. But WATCH him, so you can do it next time!
Axle shaft are the same diameter and spline count? What about the u-joint?
Axle shafts are in fact the same diameter and spline count. Actually, a very popular upgrade for the off-road crowd using the stock 1/2 ton TTB is to swap in the D50 center stub shaft to get a larger u joint in that location.