I am looking into swapping my V6 3.0L for a 5.0, in my 97 ranger XLT. It is a regular cab and doesn't weigh anything. What my only concern is, is if the 5.0L is too much power for my light truck.
Possibly a valid concern -- my solution was a Explorer LSD rear diff and raised the ratio from the stock 3.73:1 to 3.27:1.
The LSD keeps both rear tires grabbing traction and the 3.27:1 ratio helps take some of the snap out of the initial acceleration.
You could go even higher with the ratio, 3.08:1 or even as high as 2.73:1 if you really wanted to tame the power.
The Explorer diff is not "plug and play" but is well worth the effort.
I'd also suggest adding a rear sway bar if you don't already have one. The old Bronco II ones are commonly available used, as are a couple new options.
Lastly, don't build a Mustang SVT killer 5.0. Keep the engine sane! A box stock Explorer 302 is good for about 210 hp, already a huge jump from the original 3.0.