Can't find misfire

[ChevyTech]

5 degrees BTDC is to much for these trucks. Spec is zero.
Was the set timing connector unplugged when the timing was checked?
Was the trouble set by checking the timing cleared from the memory?
Have you checked for trouble codes?

WinALDL is very limited but better then nothing. It can look at sensor data. It is not much good for looking for a problem like a worn distributor.

A surge can be caused by low fuel pressure or a vacuum leak as well as other problems.
How was the fuel pressure tested?
Was a gauged installed with a T fitting?
Was a gauge used on the end of a line?
Was the pressure tested with the engine running?

And I don't have an obd1 connector.

What are you trying to tell us?
Are you saying you do not see an ALDL connector on the truck?
Are you saying you don't have a OBD1 cable to connect it to a computer and use WinALDL?
Does this mean you have not checked for trouble codes?

Have you checked to see if it has a good strong spark?
It could have a weak coil.

You mentioned you were thinking distributor module.
Did you have it tested?