convertible roll cage question?

am i correct in interpeting the rulebook in understanding that a convertible with stock floor & firewall can be certified to 8.50 w/ a standard style 10/12 point 'cage? or do i need somthing additional like a F/C cage and/or 25.5 specs? i guess my confusion comes from what NHRA/IHRA defines as the difference between convertibles & open bodied vehicles. vehicle in question is the ramcharger in my sig. pic. which will have a soft top installed.
thanks-jeff

IMO you are correct in interpreting the rules.

anymore input from the day crew?