GTX 260 and SLI Bridge

I just bought 2 XFX GTX260's that are going to be running in SLI and have a question concerning connecting them. The XFX instruction manual/installation guide is sorely lacking and does not touch up on this:

The cards came with the wide 3 way SLI bridge connector and the narrower 2 card connector. Does it matter which you use if you only have 2 cards? And if you have to use the 2 card connector which of the 2 positions on top of the card do you attach it to? There is a top and bottom since the cards are 3 way SLI compatible and it doesn't mention anything about where to connect the bridge to.

Thanks for any help.