detroit vs cummins??

I've never had issues with my ISX so my vote has to be the Cummings

 

My experience tell me cummins, had a lot better luck with my isx and ism cummins than the detroit that the company gave me to drive both in dependability and power

 

What size Detroit and what size Cummins? Size definitely matters. And what transmission is behind them, and what rear ends? You don't just buy a truck for the engine, you want them matched for your application.

 

I'd say oil analysis might be a deciding factor too.

 

my first truck was a 9200i international, 48" sleeper, ism cummins, super 10 trans. Nothing fancy but I liked it, $19k with 10 new virgin tires and a new clutch. I put $10k down and financed the rest through ge capital for 10 months. I made a lot of money with that truck and then sold it again for $25k I wish all my deals went like that.

 

I would get the one with Cummins,less power better on fuel,i'm running mostly flat roads ,but for you moving in and out of Oregon ,heavy pulling on I-5,90,84 ; imo D60 ,14L plus 13 speed is better combination for west coast roads.
I would not buy a used truck from a company running west coast; get one that's been doing light freight flat roads, at same millage should have more life in it, less wearing in motor, transmission, differentials.