The rule before was 1/2" bolt...I think it had to be Grade 8. This year's rule required the tabs to have1/2" material around the bolt hole. That rule was later revised to a 3/8" bolt for most classes (TF, NFC, TAD, and TAFC have their own specific revision). The problem with the stainless bolt may be it's not Grade 8 (though I bet any ARP stainless bolt is as strong as a "cheap" Grade 8.
How about these new rules...
http://www.nhra.com/story/2010/2/15/...-participants/
A $1000 fine for using the wrong brake cleaner????