clutch or tranny??

I have the t-45 tranny in my 98 cobra, my problem is it doesn't want to go into gear sometimes, tried several things, I put the car on jack stands and when I go to shift to first I can see that the rear wheels move with the clutch all the way pressed in. I have steeda double hook, firewall adj and adj cable with centerforce dual friction clutch. I have tried adjusting it both ways and still have the problem, it seems like the clutch is not fully disengaging for some reason any ideas??