The oil I had been using was the Morgan's Cooplower Blue oil which is their standard (?) viscosity oil mixed at 10% with 20% nitro. Some places have referred to it as their high viscosity oil.

I've recently switched to their Multi Viscosity purple oil and ran 15% oil and 30% nitro for a while, which was really nice before I reduced the oil and nitro back to 10% oil and 25% nitro, which dropped the rpm from about 7.5K to 7.2K on a 19x11 APC (I'm at 1500ft). I ran about 2 gallons of that through it but haven't really been happy so I upped the oil back up to 15% with the 25% nitro and picked up about 100rpm.

The engine seems to be more consistent on with the higher oil content so I might stick with the 15% oil for a while longer, however even though the majority of the parts were replaced while trouble shooting, some of those "new" parts probably didn't have the kindest break-in either..