[carrera]

Tim;
The main difference between the 86 and 87 is the clutch and transmision.
The 86 and earlier use the 915 trany with a cable operated clutch.
The 87 to 89 use a G50 trany with a hydraulic clutch.
The G50 is a smoother shifting and supposedly stronger trany.
This is why there is a price differential.
The newer carrera also is tuned for high octane fuel= more hp, 207 to 217?
I believe a chip upgrade will even out the performance figures.
My suggestion is to drive both transmisions for extended periods, especially the 915.
Personaly I prefer the 915 but many do not.
Take your time in your decision there are many cars out there.
Good luck.