So my 92 has been having an intermittent problem with the engine cutting out or missing at 2000 rpm and above under load. It does not happen all the time it will work fine for a day or two then come back. When the problem first came up I put in a new coil and that seemed to fix as it ran great for a couple of weeks. In my mind it would seem to be either timing advance issue or vacuum issue. Anybody have suggestions on how I could test the timing advance.
Or any other suggestions appreciated

 

apply vacuum to the advance with a hand pump, i use a pump from a blood pressure pump.
you can also use a timing light

 

Assuming your truck is up to date on its maintenance, I'd do like Drowning said and take cap off and check for advance movement. Check the vacation line incoming.