issue with AMD Demon floor pan..please help newbie

Try sitting on the floor hump with both knees on either side of the hump above the torsion bar crossmember without anything being clamped. Then you need someone to look under the car to see if the pan lines up with the crossmember. If it does then put in some zip screws to hold it in place and clamps along the edges. Thats how I had to do my floorpan to get it flush with the crossmember.