Clutch slipping in 2nd, above 4000 rpm?

[Fox Body]

92 GT 5.0, Manual (170,000 mi) Totally stock except 2-chambers Flows...

Hey, when I get down on the car, let's say I'm taking off from a light, shift to second, running it hard and looking to shift at about 5k, then at about 4000, clutch starts slipping (going in and out of transfer of power to rear wheels). I can't see it being anything else. (There is like a 1% chance that perhaps I could be wrong but i seriously doubt it). So i figure it can only get worse. Especially with summer right around the corner. Planning on getting a new clutch which should solve the problem.

I know I may be a little vague here, but doesn't this sound like a right diagnosis? New clutch will be ~$515 (parts + labor) and I'm figuring i might as well do it while I have the money.... Plus, my traction lok is dead. Only one tire gets power. Both don't. Thinking of taking care of this also.

Any suggestions... advice or other tests that I can assure myself of a correct diagnosis. Thanks guys.