Hey everyone…. Another newbe here.

I found DF while searching for a cure for my sick beast. Hopefully I can get a point or two from here to get her back on the road.

I have a 1992 B350 with 211000 miles. It has a 360 and 4 speed overdrive automatic.

Main current problem:
The timing is set to 10 BTC but when checking the timing, the mark moves almost 5 degrees either way as the engine idles.

Recent problems:
5 month old cap and rotor was spark burnt which caused rough running and backfiring and had to get towed in from the desert. (on road, not off road)
Trouble shot it down to the cap and rotor and when timing it (since I had adjusted the timing in the desert to try to get it back home before giving in to a tow) I noticed that the timing was bouncing around. Replace timing chain and gears (and waterpump, hoses, freeze plugs and belts since I had it apart) but it still bounces.
Within 30 miles, new cap showed spark burn and coil failed so I put a new coil on it.
Timing still bouncing.
It runs and drives but I don’t think I have solved the problem yet, only cleared up problems caused by the main one.

Any ideas?