I don't have the rule book handy right now, but i raced a convertible and the book clearly states that they must have a roll bar at 13.99 or faster. Plus, ANY car needs a roll bar at 11.99 or faster. I was considering another street/strip car with t-tops and two tracks told me they were classified the same as a convertible. I 'think' the rule applies to cars that DO NOT HAVE PERMANENTLY AFFIXED TOPS.
Good luck with the installation. Also, you might consider installing a 'swing-out' driver side-bar ... which will make it much easier to get in/out of the car once the steel tubing is in there with you
When the GREEN LIGHT DROPS ... the BULL**** STOPS!
1968 GTO ... 8.28 @ 162, 3050#, Pontiac 455 (474), 400hp NOS
Over 50 pictures here:
http://community.webshots.com/user/old68goat