The 66mm rule allowing 300 or 400 turbos would be nice and would benefit me as well since i just put one on my megacab. But it still doesnt make the playing field fair enough to get the normal street truck out on the track. Because the only true street trucks that can run an s400 and still be useable for the average joe is a 6.7 truck. So your cutting out a LOT of possible entries. There are a LOT of trucks out there that are running an s366 and they already meet the requirements for the class Gary has mentioned. And a truck running a 366 doesnt stand a chance against a truck with a 466, assuming they are both tuned correctly. SO if you allow both turbos, the average joe guys with 366s are not gonna enter knowing they are up against trucks with 466's.