The Pic on the left with the flat smaller flywheel is a 1967 100hp with a 15 amp alternator. This engine normally had Battery Capacitance Discharge iganition (Transistorized Solid State).
The Pic on the right with the raised type flywheel is a 1966 100hp with a 20 ampere alternator. THis engine had regular Automotive Type Ignition.
Pictures do not show the rear portion of the engines so I can't tell if the original is there or converted. Both use the distributor shown but the interior of the distributors would be different.