84-87 model wheels have the same offset.
Although some 84 fronts are 8.5" wide, others are 9.5".
All other OEM 84-87 wheels are 9.5" wide.
In 1988 new suspension geomoetry was introduced which changed the offset of the OEM wheels. This being the case, to fit 88-96 wheels to a stock 84-87 you need to use spacers front & rear. (FWIW, I understand spacers are illegal in Australia - your choice if you use them though)
All 94?-96 OEM front wheels are 8.5" wide.
90-95 ZR1 rear wheels (ie: the true 11" wide wheels with the ZR1 specific rear offset) can be fitted directly to the rear of an 84-87 Vette without modification - the wheels will fit inside the rear guard (just). These same ZR1 offset rears cannot be fitted directly to an 88-96 stock Corvette because the wheels will stick outside the rear guards. 90-95 ZR1 front wheels are the same offset as all other OEM 88-96 front rims.
96 "Grandsport" offset 11" rears will need spacers to fit inside the rear guards of an 84-87 Corvette while they are a direct bolt in for 88-96 Corvettes (they fit just inside the guard also).
The stud pattern is the same from 84-03.
Hope this makes sense.
