I need to know whether the 1995 Riviera used the first generation or second generation supercharger. Can anyone help?

I think first Generation, but not positive.

The 95 Riviera has a Series 1 3800, and uses the Eaton M62 Supercharger. The 96-99 Riviera uses the Series 2 3800, and the Eaton M90 Supercharger. The M62 has a smaller displacement, but turns faster with a smaller pulley. The M90 is a larger displacement, but turns slower due to a larger pulley. Hope that helps.