Best Oil and Coolant for CAT engines?

[GAguy912]

Rawze or other guys with more experience than me

With my Cat C12 with 700,000 plus (don’t know what oil the former guy used)
Would Shell R.T. Oil be or better choice than Dalvac?

With the claim of rods and mains been replaced what gear oil should I use? (Asking because of rail pressures problems from what I’ve read)

Also I see that they were using Lukas oil because they had a thing of it in the tool box