Crank no start, no spark.

I have a 1990 C1500, 5.7. Intermittent no start condition. I have replaced
pick up coil, ignition module, coil, cap, rotor. I have borrowed a repair manual
and followed a diagnostic ladder to try and find the issue. I have not been
able to pinpoint the problem because part way though it develops spark
again and will start. I had this issue in July. that is when I first replaced the
coil, no help. Then replaced ignition module and it was fine until a couple
weeks ago. Replaced module, was fine for a few days then issue came
back. Tried starting this morning, crank no start. Then at one point there was
nothing. No crank, no click, nothing. I have had that issue in the past also. I
am at my end with this truck!