The spring lock is broken on the belt tensioner pulley and it's not worth replacing. I donated a harbor freight torque wrench to the task of strong arming the tensioner. Belt tensioners don't work since I needed it at a 45-degree angle to start, the store ones all had 90-degree to start then 45-degree handle attachment which wouldn't work.

Didn't have the loot for an oil cooler at the time. EGR cooler snagged for $165 shipped, new. The rest of the parts got at near cost or below. Checked the oil cooler for any plugged up areas, it seemed fine.

 

I've dealt with Commonwealth, they're a bit pricy but worth it. Also heard good things about a place up off Turner near Midlo.

 

just an update...
went ahead and replaced the oil cooler.

dropped off the truck with them today. seem honest and good people. waiting to her back about injector diagnostics and testing.