Not true Gav, unless you live in the USA.
L24 was rated at 150HP (Gross)
L26 was rated at 162HP (Gross)
USA 260z was de-tuned to 140HP to meet emissions requirements, then they got hobbled again with the 5mph impact bumpers (sometimes called Nixon bumpers, since he was the President when the laws were drawn up), which added heavy impact absorbing bumpers and shock absorbers to the car, front and rear (if you've seen a picture of a 280Z you'll know what I mean). The idea was that the car should survive a 5mph impact with no damage. That pretty much killed the 260Z in the USA. Nissan upped the capacity to 2.8 (L28 170HP) to compensate for the extra weight, switched to EFI to meet emissions and rebadged it as the 280Z.
Here in Aus, emissions weren't an issue, and neither was surviving a 5mph collision undamaged.