The 410 was a stroked 390 CID, using the new 428 CID crankshaft and rods. It is unclear why Mercury chose to use this version when at the same time the new 428 was available.  It is rumored that these engines were basically 390 CID blocks that were merely fitted with the 428 CID crankshaft at the factory, though why that effort was required is unclear. It is possible that there were an excess of 390 blocks in the pipeline and this hybrid was created to eliminate the excess.

This new stroke of 3.98″ together with the bore of the 390 at 4.05″ resulted in 410 cubic inches. All other components were basic 390 CID: heads, valve size, 4-barrel intake, etc.  The 410 was only used in 1966 and 1967 Mercury vehicles. With a 10.5:1 compression ratio, it was rated at 330 HP @ 4600 RPM and 444 ft. lbs. of torque @ 2800 RPM.

In 1966 and 1967, the 428 was also available as a performance FE (called “Super Marauder”) for the full-size line. The 410 was completely replaced by the 428 CID V-8 in 1968 in the Mercury line