I know a little bit about this car ( I think). I was following this as it was happening. If I remember correctly, Keith Craft built the engine and was fitting the twin Paxton superchargers. I was interested because I had the same twin Paxton setup on my old 68 Mustang Fastback.... which I sold to start buying Cammer parts. So it goes that they had an issue (and its a pretty cool issue) that the twin paxtons superchargers were hooked up and it actually lost power on the dyno! LOL the stock "impellers" on the superchargers could not keep up with the air flow (Suction) of the Cammer Motor. I believe the owner of the cobra really wanted the twin Paxton setup, so they sent away for custom made impellers to swap into the paxtons..... which still could not keep up! However the owner really wanted the look, so they kept it on even though it was a little restrictive.
Also the Cobra was fabricated at Kirkham specifically for this application. Down to the hood which mirrors the 2 famous Paxton powered cobras made by Shelby (one of which went to Bill Cosby).
Let me know if you guys heard something different as this build was a huge impetus for me wanting the setup I have today! LOL