NHRA is pretty much sticklers about copyright issues so I'm not going to leave this up but for a short time. It's from a previous edition but the bar / cage construction hasn't changed. It's just a taste of some of the way the rules will bite you in the butt if you don't follow the book to the letter in your cage / bar construction.
Here's another example,, Like say you have removed more than 2 square feet of stock floor for trans inspection cover. (as if you had replaced the stock trans hump with aluminum) Or you have altered the stock firewall in ANY way. Then you are required to have a CAGE (no matter if you are running 8.50's or 16 seconds, CAGE, not even a bar but CAGE) . You got bit in the proverbial azz by the rules. To further the pain,, if you are required by the rules to have a cage, then you are required to have a SFI window net. NO EXCEPTIONS, if you are required to have a cage, then you HAVE to have a SFI window net. Point I'm getting at is if you step over the line in one area, it will force you to comply with a boatload of other CRAP to ever get through tect and out on the track.
Like jgh... said there are some tracks around that simply don't care and won't tech you at all. Good luck with that is all I can say. There is a IHRA track in Tulsa so some research might give you an idea if there is a difference, but as far as I know NHRA and IHRA are pretty much in harmony on the bar / cage rules.