240/260z's have r180's...all 280z's have r200's.
Not exactly.... the 280Z car (75 through '78) came with an R-200 rear end. All automatics of these years were R-180s. The 280ZX '79-'83 were as follows:
All years 280zx non turbo automatics were R-180
All years 280zx turbo automatics were R-200
The '79 280zx coupe 4 or 5 spd were R-180
The '79 280zx GL and the 2+2 4 or 5 spd were all R-200
All '80-'83 manuals and '83 manual turbo were R-200
All 300ZX '83-'89? were R-200
All '84-'86 200SX were R-200