All depends on the backspacing of the wheels. If you haven't seen it yet, there's a good sticky over on LS1tech that describes how to measure, what wheel widths, and what backspacing combos work well and which ones require mods to fenders or addition of spacers.
I had my rear 2002 style WS6's widened this winter by Weldcraft. To get the backspacing correct, I'm also running the 1.25" spacers.
Later!