One of my neighbors brought over an engine for testing. It's Johnson CS. It lacked an NVA and had a stripped pressure fitting. I put in a OS 40 NVA and retapped the hole to 6-32.
It started right up on 15% with a 10/6 and did 10,000 RPM on suction. No doubt it can do more on pressure with a smaller prop & more nitro.
If a vintage combat builder is interested, let us know.