From Ford Wiki

Ford Motor Company's Lincoln division has produced three distinct Lincoln V12 engines:

• 1932–1942 L-heads:
  • 1932–1933 Lincoln L-head V12 engine
  • 1933–1942 Lincoln L-head V12 engine
• 1936–1948 Flatheads:
  • 1936–1948 Lincoln-Zephyr V12 engine