A very good question.
I looked in my '80 parts manual (only):
’80 L-body (Omni/Horizon) had two versions: a 2-door and a 4-door hood.
'80 F-body had one hood part number.
M-body had one-part number (different from the F).
'80 J-body (Dodge and Chrysler) had one-part number.
'80 R-body had two versions: Dodge, Plymouth and low-level Chrysler (Newport) shares one and high-end Chrysler (New Yorker) has a different part number.
A total of seven different hoods used for passenger cars.
BudW