Sent inquiries to the Engine Masters Challenge Tech/Program Directors and Jon Kaase, winner of the Challenge, regarding the FE question.
Jon Kaase Racing Engines web site;
http://www.jonkaaseracingengines.com/
Copied from the 2003 Rules:
ENGINE
Any normally aspirated, domestic V-8 big-block engine is acceptable. Maximum displacement is 470.0 cubic inches. Power adders such as superchargers, turbochargers, nitrous oxide, or other such devices, are not allowed. Factory small-block engines and Olds Diesel-based engines are not allowed. Traditional Pontiac V-8 engines are acceptable.
ENGINE BLOCK
Any commercially-available cast (iron or aluminum) engine block is acceptable. Engine block must retain OEM cylinder bore spacing. Lifter bores must retain OEM angle (+ or -1 degree) and OEM diameter (+ or - .005-inch) as originally cast. Engine blocks must retain OEM deck height or lower (exception; Chevrolet Gen V and Gen VI "tall-deck" blocks are acceptable). Aftermarket tall-deck blocks, including the World Superblock, are not allowed. Block must be equipped with solid engine mounts.