I got to admit that I'm scratching my head over what your goal with this build is. 31s on a first gen make me think off road build. Then you say that they are going on Explorer 20" wheels so street truck or mall crawler. A.5" sidewall is a little big for bling factor, but a little low for off-road IMO. Then you say dana 30 solid front axle, back to off road rig. Throw in the mismatched flare side bed, unless you plan to change the bed sides.
I'm not knocking it, I'm just real curious as to what your goal is and how it will end up. FWIW I'm going against the grain with my '99, but seems like a different goal. It's probably getting dropped over Explorer 18" wheels, about a 29" tire (until I can go lower), 5.0 swapped with an AWD drivetrain. I'm not the only member to do it, but definitely not the norm