The thicker the spacer is, the more loading and wear on the hub bearings.
Best is mount the other wheels/tires on your Vette as what the offset may be and see how it fits/looks
For my 1999 C5 I went with 18 inch front and rear
Front wheels are 10 inches wide and use 275/35/18 and
Rears wheels are 12 inches wide and use 335/30/18,
but I choose no offset and instead mini tubed to gain 1 1/2 inches per side