Neal..I DONT think you have head work or cams , your times match your mods, shifting at 5800 and 4 blown head gaskets dont sound right, but i dont know you situation.

i am amazed that some people gets denied repairs for having a chip and you get 3 head gaskets replaced with no problem, you must know someone there, all the more reason to have a set of heads ready to go with gaskets and ask the mechanic to put this set on.

 

HI!... That's the last time I'll bring my truck to the dealer. I'll be doing the head gaskets myself this time with help from a friend.

 

I pulled the connector off the Cyl #1 injector to test it. It seemed like it wasn't seated all the way. Maybe I goofed when I did the plug change .
The DTC's (P0147 and P0262) went away after I did that. So has the ping. Shift point is now at 5250, running great.
So do DTC's clear even if you don't reset the comp?