wheel spacers
Wheel spacers are not a good thing, if we are talking about the same thing.
See picture below, these are the type of spacer I'm talking about, where you bolt them to the hub, then mount the wheel to the spacer.
There is a good possibility of throwing off your rear allighnment with them, also being a rear wheel drive car, there will be excessive torque on the hub specially on quick starts. Depneding on the manufacturer and machining tolerances some are worse then others.
They may be OK on a 1967 Nova with low rider rims etc.. if you know what I mean, but on a highly engineered precision machine they will cause a proformace loss and extra wear & tear on bog dollar tires.
Best way to be sure proformance is increased insted of decreased is to invest in larger/wider rims. If your only concerned with looks and don;t care about the rest, then try it out and let us know how they work. At first when you put them on then agaon about 12k miles later, keep track of tire wear and let us know.