MJW
I understand your pain man. I am dealing with my 01 550 right now, oil leak, after leak, after leak. Gutted the pedestal and blew out the backpressure valve yesterday. Had endless fuel system problems last week, lost the CPS HPOP o-rings, and ABS problems the week before.
Now, this is my service truck, reliability is key. Soooooo.....
Today I am looking at a T270 Kenworth... With a cummins.
Good luck with whatever path you take.