My personal truck and 5 other trucks I know have been running Specs Stage 3 Clutch for a Dodge for quite some time now. Three of them are 24 valves, and 2 are 12 valves. Ranging from 300-500hp.
My personal Truck is a 24 valve. I have been running this clutch for about 2 years now. I have sled pulled with this clutch about 15 times and it has held up to my abuse on the street also. My truck is at 500 hp, and 950-1000 ft/lbs of torque. The only dislike I do not like about this clutch is that it is quite grabby, which you learn to live with. For the price this is the best holding single disc clutch.
I am actually getting ready to pull this clutch out soon to upgrade to a dual-disc clutch. I am anxious to see what it looks like.
If anybody has any other questions feel free to ask.
Bill