Well-just turned 300,000 on the truck. Changed glow plugs and did compression check on left bank today 340 325 360 340 on cold motor. changed gp relay and icp sensor also. tomorrow if weather holds(no rain) im doing right bank and rebuilding hpop and new seals in fuel filter bowl. Amazing but heads were super clean-no sludge -carbon -nothing-super clean everywhere for the mileage. Any suggestions on things to look for while im at it?