Just what I figured

[cougar]

Got my 91 back from Cummins Wednesday and they confirmed and corrected what I suspected. The PO had the pump gear advanced a tooth. The tech reset the gear and pump timing back to the stock 1.25mm lift. Mine was actually laboring under the advance. He said that pump timing should match the injectors you have. Though mine are +40, they still operate at the same pressure as the stock ones. The results were dramatic. A quieter, smoother running engine with a 5psi increase in boost, less lag, and lower yet EGTs. Still smokes like s coal burner though
Next is to try the timing spacer again and then get the HTT on.

[JBradley500]

That's good to know lol! If i ever sell my truck i hope to remember enough about the things i did to it so the next owner isnt left in the dark.

I know what youre saying about quieter, the sound difference between where i am now and what it sounds like with 6* less timing is a huge difference. I dont like the extra noise very much, but without that extra timing it ran pretty poorly.

[cougar]

At least you have the injectors for it.

I reinstalled the M&H dynamic timing device. This time no weirdness. My idle stayed the same and I didn't notice a power loss this time. I'll have to put it through its paces to see if there is any change.