AutoZone plug wires are crap, they will not last.
www.apexperformence.net and order 8mm Magnecor plug wires, once they come in put them on your truck and return the Duralast plug wires for a full refund as they have a lifetime warrenty.
Thats what I did.
I had a set go bad inside a month.
Sounds to me like you have sprak leaking out of the wires and shrting to the block.
Tonight when it is dark open the hood and start the truck and look for sparks.
Spray the plug wires with a water bottle and it will really show you were they are leaking from.

 

I will try that. Can bad plug wires only cause issues while the engine is under a heavy strain, like the uphill drive i did today?

 

Yes they can, weak spark will cause power loss.

 

Wrong Octane fuel or bad knock sensors.
But could be any number of things needs a more hands on.

 

Truck also seems to shift out of 1st gear very early when I start from a stop. It seems to run through 2nd gear very quickly also. What controls how fast the truck shifts?

 

The only thing that controls how the truck shifts is your foot on the throttle.
Until you do your tune up there is really nothing more that you can do.
A poorly running engine will mess up otherthings too.

 

I did not see anything arc while looking at the engine in complete darkness last night. Going to try the water test later tonight. Could the timing possibly be off just a little? I had to replace the vaccuum advance on the distributor about 3 months ago.

 

Yes it is possible that the timing is off.
Did you replace the vacuum advance or the vacuum advance hose?

 

vacuum advance

 

Do you have a timing light?
If so set the timing and then see what happens, I still highly recommend the new plugs and wires though even if setting the timing fixes it.
Sorry I didnt notice that you had a '95 from the beginning.