Changing plugs and wires on this is eminently "do-able," but that doesn't mean it's a piece of cake. In fact, it's a PITA! Biggest problem is that the rear half of the engine is tucked under the cowl on these trucks...to accommodate the steep windshield rake. That means half the plugs on each side are hard to work on. To make matters worse, the plugs on the passenger side slant toward the back of the block; the driver's side toward the front (which makes them easier to get to).
Just be prepared for an afternoon of cursing and bloody knuckles. Make sure you have a socket set with LOTS of extensions and universal knuckles. I would also replace the coil packs on each cylinder bank.