NHRA rules ??

if you pass the basic tech requirements....lug nuts....radiator overflow...battery 3/8 bolts tie down...seat belts...you are good to 13 flat..

then you need a Snell 2010 or newer helmet....down to 11.49

after 11.49 ..it starts with roll bar and 6 point seat bells...

our tech will generally ask how fast do you think it will run???
13.99 or quicker needs a helmet - UNLESS - you have T-tops, convertible, or sun roof, then you need one regardless of ET.