Some people will tell you Schaeffer's 7000 is the only Blend being sold as a Blend in the USA.
25% PAO + Group II+ may have a higher natural VI than some Group III Synthetics. I can name one 5W-30 that I know is only around 125 VI for the basestock.
You need not worry about the 6.2 OHC. Feed it any viscosity from 5W20 to 15W40 with 7500 mi OCI and it will survive just fine.