^ Well Over 600hp with stock internals actually, depending on your setup & such it’s able to take a lot of punishment, but over the course with proper maintenance to boot, remember cooling is especially important as well…
also with the earlier RB motors, there were minor oiling issues and such
so if those are figured out and everything is stable then pushing it to such power capacity by use of bigger turbos and such is easy on stock internals/bottom end.
& as for the VR38, there’s articles out there that are estimating and testing out huge power gains and potential…also put in the fact of the larger displacement as well…only time will tell 