just about all newer vette's come from the factory with mobil 1 synthetic oil installed and is recommended, 5w-40 or 10w-40 will work fine.
motor oil 10w30
synthetic oil
You should use 327ci 300hp 1966 Corvette engine oil ;)
10-40 or 15-40
r12
You can use Mobil 1 if you desire, but you can also use conventional oil.
One reason was it was the last model year to use a carburetor.
Valvoline premium conventional 5 or 10w30
i use synthetic oil,it doesn't break down like regular 10w30
Mobil 1 synthetic.
R134A
10w30 in the summer and 10w40 in the winter.