Mystery over. Not aircraft.My friend a found an ad in his search.That Mfg also made heads and intakes for the conversion for 4cyl and flathead V8.These conversions were designed for the Gazogene Conversion.Here is a link that I found on Google.
https://www.google.com/url?sa=t&rct=...Wk3umqJ-6peQdH
Here is the ad my friend found.The head has compression rating of 8 according to the ad.