I was wondering the same thing. I looked on the SCORE website, and the "Pro Stock UTV - NA and FI" rules are very different than Pro UTV NA or Pro UTV FI. For example, NO AFTERMARKET SUSPENSION is allowed except for tie rods and radius rods, but reinforcing material can be added as long as stock dimensions are retained. You must use OEM steering components, except aftermarket ball joints w/ OEM fitment. Surprisingly it states you can use the OEM fuel tank, but must install an "additional rear tubing bar for protection." In my opinion, I'm not sure if this is the best place to save money since a fuel cell is not a performance item. It says you must use OEM radiator in stock location. Must use OEM clutch. And I didn't see it spelled out, but I'm assuming you must retain the OEM frame not just the OEM pivot points. If not, then I'm completely confused about the intent of this class. Overall this class seems like a good idea to me. Hopefully it will help keep costs down and show which UTV manufacturers are stronger out of the box, and not what team can build the best full-blown, purpose-built, tig-welded racecar that "appears" to look like a stock UTV.