which oil for Ray Barton engine

Hi folks,

i just bought a new A-body toy. Has a 528" Ray Barton Hemi inside.
The pre owner used a straight valvoline W40 oil with ZDP for a better lubrication.

What oil do you prefer? Its a physical to find the right oil. I'm located in Germany and the most lubrications are different than the US ones.

ideas welcome...

thx JAN