they're better than everybody says they are, but when pulling really heavy loads and wanting to use the power, ... they will slip. But i am talking about 29,000 #'s and over number 2 on my tst comp box. if i'm below 2, then it won't slip. But in 4 wd low, i have pulled 39,000#'s with the comp box all the way up and propane on!!! That was a big load. So they are good clutch's, but next time i'm going with south bend's big clutch, mitchels, pulling clutch, and hadley's machine shop's pulling clutch, ... but these will be a lot more pricier though.