A potential problem I see is Scuba Tanks don't hold much more then 90 Cu Ft of air. I never caught anything in the article about just how long the engine could "run" on the two tanks pictured, but the pressure potentially could fall like a rock with those large -20AN lines and mega regulator at full power. Check the B&W picture of Mickey Thompson posing with his own "bottle fed" Boss 429 motor in 1971.
http://www.hotrod.com/techarticles/1410_compressed_air_supercharging/
