What would you delete?

Wow, amazed at all the responses, thanks to all. First, regarding my 6L Ford, I did not have anything deleted (to my dismay) and paid the price when the head gaskets blew in St. Ignace. I did find someone to tow my 5er home, no problem. The biggest thing I wonder about with my Cummins is soot build-up. The egr in the Ford was first domino that led to the head gasket blow out and dont ever want to go through that again. Just want to make sure the soot build up (there must be some) won't be an issue. I do have the engine brake on all the time and most of my runs on on the expressway, not many short trips. Finally, there is not currently and emission testing required where I live (Michigan).