Ross, I think you mean the Chevron Delo-400. It is CH rated and a great buy at Costco warehouses. That's what I run in my diesel!
Andy, personally I wouldn't change it right away. I'm not saying M-1 is bad oil, it's very good oil and will not harm your engine in any way. If the noise is valve related, well slightly loose valves are better than tight ones and only annoy and embarrass.
If you've developed the slight leak problem, well going back to Dino will not immediately eliminate that. (don't don't place any stopleak garbage in your engine).
Take your trip with confidence, of course check everything you normally would before taking a long trip. Wait until you've gotten some use out of the M-1 and then switch back to Castrol.
You won't go wrong there!
Ed "Don't Benz's just feel better..."
2000 ML430 Skyview "The Mel"
2000 CLK430 Cab "The Cab"
85 300D Turbo "The Diesel"
"One should as a rule respect public opinion in so far as is necessary to
avoid starvation and to keep out of prison, but anything that goes beyond
this is voluntary submission to an unnecessary tyranny, and is likely to
interfere with happiness in all kinds of ways."