Corvette Action Center | Tech Center | Model Center
and Model Center info here: Corvette Action Center | Model Center | C4 | 1996 Corvette | 1996 Corvette Production Numbers
1996 Total production was 21,536 units
Black total production was 3917 =18% of total (21,536)
Total convertibles produced was 4369
CE LT4 convertibles produced was - 469 = 3900 non-CE convertibles were produced
If you extrapolate 18% (percentage of Black Corvettes produced) of the 3900 non-CE LT4 convertibles
you get 702.
At least that's what I come up with. Someone may be able to get you closer to the ballpark.