Just noticed, in your original post, you said the spark at the plugs was orange.  The spark should be white with maybe a slightly bluish tint.  You can also check if it's the plug or something further up the line by sticking a screwdriver in the plug socket at the end of the wire and holding it close to a ground.  The arc should be able to jump at least an inch from the screwdriver to the ground.  Careful not to bugger up the socket with the screwdriver though.

Moving on to fuel:  You said a new pump and filter was installed.  Why? Obviously a filter is a normal maintenance issue, but was it clogged?  How long has the truck been sitting?  Is it possible the gas has soured?  If so, the injectors could be clogged?  Can you smell gas coming out of the tail pipe?  Something you can also try to make sure fuel is getting all the way to the cylinders is to pull all the spark plugs and try to start it.  Check and see if you can see/smell puffs of gas coming from the plug holes.

I realize I'm mostly asking you more questions, but this is kind of the way I go about diagnosing such a situation.