The first change to the Z line was with the short lived 260Z with its larger 2.6 liter engine, increased from the original 2.4 liter with the first generation 240Z models. The new 280Z emerged in 1975 with a 2.8 liter engine. Finally, in 1977 the 280Z gained the fuel injected version.
In August 1977, Nissan begain closing the book on the original Z car design with its 1978 model year 280Z, what many believe was the finest original Z car ever built. Production on the last original Z car was completed in June, 1978.
What followed in the coming years starting with the 1979 model year were, in my opinion, cars which reflected an evolution slowly towards a GT and more luxury oriented sports car. Over time, I believe the there was a continued diminishing of the DNA of the original Z car. Although the 1979 280ZX possessed much of the original Z car's personality, the trend as the years passed was a fading of the original Z car's heritage. While later model Z cars are decendents of the original, including the latest offering by Nissan, the 350Z, possessing some of its original spirit, to me the 1970 - 1978 model years, will forever assure its place in 20th century automotive history.
And finally, Grandpa Dave's car