Thats not true. My 96 9c1 has 94-96 ss wheels that came on my 95 civi. The civi now has alloys and uses police package steelies in the winter. '90 to '91-'06 are the only difference I think. So, all bubble caprice wheels are interchangeable with the SS. The SS does not have the same rear as a 9C1. It has the same gear ratio,and G80 was also an option, but the carriers are different by 5/8 inch width on both sides. 9C1 rears are narrow to fit snow chains for municipal use.
96 9C1 LT1, lowered, Z28/ST, ZQ8, Belltechs, posi/3.08, shaved SS trunk,spoiler, Buick brace,tubular extended RCA, cowl hood,91/92 tails, CAI, console shifter, RM leather buckets, manual seats/windows, 9C1 wipers, Cat back and more