Chris-Craft used "Marine Power" branding from the mid '70s until the engine division was sold to Bayliner US Marine in 1983, at which point it became "US Marine Power". My engine manuals show three different version of the engine number plates for the 454s, one said "Chris-Craft", another version had "Chris-Craft Marine Power" and the third was just "Marine Power". I think they used the "Marine Power" version for the engines they sold to other builders. Hatteras and Bayliner both used Chris-Craft gasoline engines in the '70s.
As for engine oil, if I recall from the 1974 350Q manuals from my parents' former 35DC, Chris-Craft specified SAE30 as the preferable choice followed by 10W40 if multi-grade was used (check your manual for accuracy). Using something with suitable anti-wear properties for the non-roller cams is likely important.
Another option to consider is the Quicksilver 25W40 (as recommended by MerCruiser) or Rotella 15W40 T4 (as was recommended by Crusader for years).