Bmw M5 rims are staggered and look like they would fit the offset of the early c4s. I have a link with offset measurements do you think they would fit and look good? Any one running these on their C4? http://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=262985884234&category=43953&pm=1&ds=0&t=1501133499000&ver=0

I don't know if they'll fit, but, IMO, I don't think they will look good on the C4 body design/profile.

19 x 8.5 and 19 x 9.5 seems rather narrow for a Corvette.   The offset is okay.   The link doesn't list the bolt pattern.   You need 5 lugs on 120.7 mm (4.75") diameter.   The center bore is critical, as the wheel should align to the center diameter of the hub.   I can't find that dimension for the Corvette.   What size tire is normally used on the BMW?   A different outside diameter of your tire will affect your speedometer calibration.