you don't need special lug nuts for IROC wheels- just get good aftermarket chrome "acorn" lugs, and you are good to go.
the IROCS do fit- i've seen several older Camaros with them and had a set on my Nova. in my case at least, they do tend to stick in too much on the front, and out to much on the rears. i don't see how you could switch them front to rear- the wheele bearing dust cover on the front will poke out thru the center of a rear IROC wheel. with 225/60's on the front, it would rub on the subframe at the rear at full lock, and 235/60 on the rear will BARELY clear the outer wheel well on my nova- but a Camaro might be different. i got a set of late 80's Trans AM GTA wheels, and they fit perfect. everything is centered with the same clearance on the inside and outside of all the rims, and 255/50/16 tires fit perfect. plus, i think they look better.
you don't plan sincerity.
you have to make it up on the spot.
wanna hear about 20 years ago when i was too smart to know any better?