A howling noise in the rear end.

The noise is most likely a worn pinion gear bearing. There are 2 bearings on the pinion. The diff will have to come apart to inspect/service the bearings

Not sure what your looking for , but give this a try
diagram 1997 ford ranger 2 3 liter engine 4 cylinder stick shift five...

If you are mechanically inclined make sure the number four wire is tight at both ends. at the spark plug end see if you can wiggle the plug, make sure it is tight and gapped properly.

I recommened only the factory part for this. You can buy it from most full service part stores and not just the Ford dealer. The part is
MOTORCRAFT Part # DY959 [ICM] (Ignition control module) $176.79
You can also mail order it from a site I use called rockauto.com the price given above is from that site.

THE ONE HEAR THE RADIATOR ( FRONT ONE )

clunking or grinding noises, wont accelerate to full potential,

1991-1994 2.9L and 3.0L Engines Firing Order 1-4-2-5-3-6 1995 And Later 3.0L V-6 With DIS Ignition System Firing Order 1-4-2-5-3-6
4.0L Engines Firing Order: 1-4-2-5-3-6 DIS Ignition System

check the gear lube in resr end. if its low it will cause it to howl

Remove the drums and check your rear brakes. If okay, you may try testing a couple different tires in the rear. Belts separating and flat spots show worse at higher speeds.
It could be bearings if truck is used alot while loaded. Remember 1/4 ton is only 500lbs. High miles, hard driving, or if it was wrecked in rear could all cause these smptoms.