With the steering wheel turned to at-or-near the limit when in 4WD, I get a lot of pulsation through the steering wheel. Is this normal, or is the truck bent?

'94 F150-manual trans - hubs.

 

That's hard to say. With a '94, you have a U - joint in each axle shaft at the end of each Traction Beam of your Twin Traction Beam suspension. These are regular U - joints, not Constant Velocity (CV) joints. With it over to the lock, the drive angle of the U-joints is at maximum angle, and they will do a speed-up-slow-down dance as they rotate. Normally on loose surfaces, it's not too noticable. If you are doing this on dry pavement... don't! If it's doing this on looser surfaces, and is real noticable, your axle shaft u-joints may be worn.
Readers of '97 an on F-150's, ignore this, your setup is totally different!