6pt or 8pt roll bar is good up to 10.00's & Slower. 9.99 and faster the vehicle must utilized a 10pt NHRA Certified roll cage. Technicly, NHRA rules state that the rear down tubes from the main hoop must be fully welded. They usually don't give too much trouble about this, but the main hoop's cross bar MUST be welded. Bolting to the floor is legal if the plates are 6" X 6" and 4-Grade 8 or better bolts/nuts are used per plate. A 6pt or 9pt roll bar does not have to be certified.

I would steer clear of Autopower, they use cheap material (thin in some cases) and I've seen 3 or 4 welds crack because the welder did not burn-in the weld correctly. It's about safety, so this area does not need to be skimped out on...

And you can order the NHRA Rule book online.... http://store.nhra.com/product.asp?0=230&1=231&3=54