The base comes with 495 470 direct from Chevy's website. Doesn't say anything about it being a Z51 option.
Horsepower and Torque
The 2020 Corvette delivers 495 horsepower† and 470 lb.-ft. of torque† making it the most powerful production Stingray ever.
HORSEPOWER
495
TORQUE
470 lb.-ft.
What does the asterisk denote?