My old tank had a stick-on foam rubber mat attached to the top. The new tank did not have this. Is this a sound deadened for the tank or to keep the tank from rubbing metal to metal against the frame of the car? Can I install the new one without the mat?
The old foam rubber mat provided both sound deadener and metal to metal contact to a minimum. I would definitely use a rubber matting of some type in between tank and frame. Just remember the thicker the material, the harder it will be to get the two (1/2") retaining bolts started. It will be worth the trouble in the long run.