Yeah, when your engine torques forward and backward, that mount normally will hold it in place. Using only two mounts will 1, put alot more stress on those 2 mounts and 2, torque forward or backward more under accelleration creating unwanted handling.
Sorry didn't have time to post the pic last night, here it is:
The black bracket u can see in the pics is the engine mounting bracket. The silver piece is the mount itself. The black bracket is probably what u need. It's actually a large bracket attached with I think 2 bolts to the engine. U need to get the bracket from a 90-93 integra ls, and the 2 bolts.