Rule in question is from Arkansas Outlaw Racers- Real Street Class
#20: Big Block Heads: All Big Blocks-No Big Chiefts, No Big Dukes etc. Conventional Heads ONLY. Must be style of head from a Production Vechicle.
As the rules are worded they are legal. Nothing about how many where made(1,200) or nothing saying no HEMI style head. This at some point will also come up with the Mopar fans about Hemi head legal or not, and also by the way the rules read they would be legal at this time.