Try an 89 but it might not be pinging. Exhaust leak will sound like a knock. The smaller the leak, the louder the knock. There isn't a washer sitting on top of one of your pistons is there. Been there done that. Check your plugs for damage too. Don't adjust timing around a knock. Adjust timing where it should be and find/fix the knock
That's one of the problems, I don't know where the timing IS supposed to be. According to your info, My timing should be about 13 degrees BTDC.
My EGR has been crimped off, so I'd have to get a new one in order to put it back into service (which is supposed to be one fix for engine knock)
My Spark plugs are fine (I had them out recently to re-gap them) but they are those 4 electrode ones (with the cross in them).
The knock only occurs when I floor it (under heaviest load)
So I don't know what else to do.