I am looking at replacing my clutch with either a hays or ram hd clutch anyone ever use a hays clutch?

I currently have a spec stage III but I am still having problems with my clutch When in the upper rpm's and hard to full throttle the clutch seem to disengage and the rpm's jump way up I will get off the gas and then get on very light it seem to be o.k. I does not do it all the time I have a oil leak possibly rear main and I have also replaced the slave unit with a new one and replaced the rear main when I put in the spec clutc and resurfaced the fly wheel.

Anyway I am gonna pull the trans and see what is going on.