Is it the head gasket? Please help diagnose.....

[Megadad]

Glad you got it figured out. Post 9, 11, 12, 13, +++ called it.

Yeah its running well and they sure did

 

[coal_roller13]

Also if you want an exhaust brake this is the best route with your current setup.

https://ca.bddiesel.com/products/electronic-exhaust-brake-4-0in-ram-2500-3500-6-7l-cummins-2007-5-2017?variant=40504350900278