Does anybody have the requirements for driveshaft safety loops?  I realize that you can make them out of anything, however I'd like to know the rules from NHRA or any other sanctioning body.  I'm planning to use flat stock, as I can bend that as I need into shape.
Size of flat metal stock?  Width and thickness?  
Or if tube stock is used, OD and wall thickness?
And is there a requirement for front loops vs. rear loops?
And mounting requirements?  To body sheet metal vs. frame mount?
Thanks Everybody!!
 
 