We're working with a '65 Mustang with two-piece engine mounts. Ford used this mount through early 1966, then developed a new one-piece mount designed to reduce noise, vibration, and harshness. This new mount also made the engine sit lower, which explains why a '65 Mustang feels a bit different from mid-'66 and later. Ramon's Automotive in Palmdale, California, properly supports the engine, locating a 2x4 at the oil pan riser in front. Never support mid-pan.