Yes the bracket that bolts to the intake is a physicly different piece that puts the pivot and linkage in a different position on a 2 barrel rather than a 4 barrel.

Basicly all you need is that bracket itself. you can reuse the rest of the linkage parts. I might be able to dig up an example of both to show you the difference.
I also believe the 4 barrel one is reproduced. Mancini Racing sells them if I remember correctly.