My truck is an 08 F250 w/ 6.4 Sparton tuned ,just chiming in about my Valair $1k Ceramic/kevlar singel disk clutch, really my 2nd Valair, the 1st wouldn't hold in 2nd gear on a wet road. The pedal pressure went from 45# to over 80#s an 80% increase from a 25% plate load increase.In two weeks of calling and some 15 calls Dan" the guy you need to talk to" wasn't in or didn"t he return my call. This Valair deal has been going on for about 8 months I tried the first clutch about 3k miles while their dual disk was being developed, Dan said when it was ready I should try it and if they found anything wrong with the 1st one he would offset some off the cost to up grade for thelabor to change clutches, sounded fair. Before I spent more money I asked for some names of the guys to ask about their opinion of the DD, the only report was from the man whose truck Dan used to prototype the clutch, still I said OK, I was already into this thing $1k, send me one but first what sort of $ are you thinking. Then Dan took back his offer to help with the labor cost and said I'll just send the new improved ceramic/kevlar singel disk That is the one in my truck today and I'm the guy with the limp from driving with the Valair clutch. The line in their add about "you'll like it, we guarantee it" realy didn't work for me