The metal cover of the pressure plate will be close to 1/4" away from the flywheel until you tighten the bolts down all the way. That's what compresses the spring and sandwiches the clutch disc tight against the flywheel. If the gap didn't exist, the clutch would slip and wouldn't drive the transmission. When you depress the clutch pedal, the diaphragm spring is compressed further and the pressure plate is drawn away from the disc to allow gear shifting. To avoid distorting the cover, turn all the bolts down evenly, maybe 1/2 turn at a time, until they bottom out. It the bolts are 3/8" (9/16" bolt head) torque them to about 35 ft/lbs.
Jerry