[AUDIOGUY]

I have always tested clutch "grab" by putting the car in top gear.... ie 5th or 6th depending on your car at about 25 mph and pressing the accelerator to the floor.
This will show if your clutch slips or not. Watch the rpms and the mph needle they should climb together at the same rate. If the clutch is going to slip, you will know it.
The rpms will jump up and the car will not accelerate.

Best of luck...

By the way, I get over 72 mph out of second in my car???