Where can I find what I need to get 4.11 or 3.73 gears on the diferential on...

["S"win]

...my 96 firebird its a V6? I looked alot online and couldn't find it, just for v8 does anyone know a good site where I buy one from?
right now the gears are 3.08 i think.

 

[Goatman]

The gears are the same for both the V/8 and V/6 cars there are no internal differences ..