Peter built this clutch for my twin turbo truck, it has a 3850 pressure plate with the 4200 discs which are supposed to be better and let heat away quicker, i know theres a difference because i had tjust the 3850 and when he sent me the new one the discs were way different. This clutch has less than 1,000 miles on it and probably 3 or 4 hooks. Its like new and the only reason for upgrading is to go to a triple disc. i had over 2,000 in it new and will take $1,400 shipped. I need it gone for money for my triple disc. thanks allot and pm me with any questions.:rockwoot: