Yeah, unless you're lucky and your version supports dd-wrt, you can pretty much forget about it.
I've never understood why Belkin has made so many revisions to this model. They've been selling this same model since (iirc) 2003. They must have changed the revision a couple dozen times by now, which is ridiculous. It makes it very hard to say what you can and can't do since that varies w/ each revision.
For example, I have a small WDS-based, bridged network using these same routers. However, mine are also ancient (probably one of the earliest revisions). The early revisions supported WDS, then Belkin removed it at some point (don't recall when). Even if you had these same revisions, Belkin's WDS implementation was limited to WEP, so the issue is probably moot.
So unless you're just lucky to have dd-wrt compatibility (and iirc, dd-wrt installation on these routers was a bit tricky and easier to brick), you're simply not going to be able to bridge these routers over wireless.