Re: Question about ebay black ZR1 wheels
They don't require a spacer, but the rears tuck in a lot. And if your truck is lowered, then I would say that a rear spacer is required for safety, as the inner tires come within 1/32 of an inch of the shackles, depending on your setup of course.
Stockish power, get a 1" spacer. Making good power, get a half inch spacer and longer studs.