I don't know of any for the Nova. GM offered them from GMPP for the Monza and the Vega for TransAm racing and they also had fender flairs and ground affects for the second generation Camaro to mount bigger racing tires on the car.
MAS Racing Products
2288 University Avenue
St. Paul, MN 55114
part # for front - 1848
part # for rear - 1849
They should be on internet also.
They used to be called Racing Unlimited.
I bought rears about 2009. They will cover 4"-5" wider than stock, and larger diameter than stock. Mine are still in box. They look like old IROC flares.:hurray: Love the old school look!!!