After looking into your past posts, it seems evident that you may need to do some things that you may have missed.
http://67-72chevytrucks.com/vboard/s...ap#post8403508
In that post you claim you had starting issues from last year and changed the cap and rotor but never mentioned the possibly fouled plugs. So what about the plugs?
In the event of fouled plugs and driving for extended periods, a cylinder problem can ensue. read washed down cylinder walls.
I have chased down a problem with caps and rotors not lasting 300 miles due to a plugged up vent in the distributor. Were the vents ever checked?
I have had starting issues due to a bad cap that one day seems fine and the next day won't start. I found out that just 3 plugs not firing will cause a no start situation.
We can get into fuel pressure later but we want to know about these issues.