Well I have to replace my clutch and I think I am gonna go with a centerforce unit. So I go to order it and it turns out that its not quite that simple. I dont know which type to get or the size. So I looked up on Summitracing.com and found my specific application and it was a 12 inch. So then I asked a friend what one to get and he said an 11 inch Dual friction. What size is the input shaft? It is a 10 spline right? It is a 465 out of an 84 K10. What gives here and which one would you put in your truck?