I've got an Eaton 400 and 3.73 set in my ride. If I had to do it over again, I would probably go with the 3.42s. Don't get me wrong, the 3.73s are great for launch, but murder on your wallet when it comes to fill it up after driving it like you stole it. Plus, the 3.42s are a little better on the highway for mileage. I didn't do the install myself, I don't have the mics for it, plus I've never done one before. I may do the rear end on my old chevy truck, only because I want to install a posi in it. But the truck has a lot more room and it's not a show car. hehehe.