The '53 Lincoln engine wasn't just larger than the '53 Mercury engine, it was much more modern. '53 was the last year for American production of the old Ford flathead V8 introduced in '32. By '53 it was pretty outdated, although Simca made it in France through '61. Lincoln introduced a new overhead valve V8 for '52 which was quite a good performer, thus ensuring that in '52 and '53 Lincolns were much more powerful than Mercurys. In '54 Mercury and Ford got their first overhead valve V8s, not as large as the Lincoln engine but of similar modern design.