So i went to go install my 10.5 inch ram hdx clutch kit and its too small for my car. I took a tape measure and i measured 11.5 inch surface diameter on the stock pp and disc that was in the car. So before i send my wrong clutch back to summit and get a new one, what size to i need? The only other size i can see on their website is a 11 inch clutch whih still doesnt seem right. Anyone wanna help?