In 1980 the standard Valve covers were upgraded to the Turbo version. They are stiffened with ribs and less prone to leak.
Compression went up from 8.6 to 9.3, but no HP increase.
I think the 3 spoke wheel that was first on the Turbo and early Carreras became standard, although the grip was not as thick / fat.
Larger cooling fan from Turbo, as mentioned.
Improved crankcase oil scavenging.
Oxygen sensor added.
And the smog air pump that is belt driven was deleted.
