Not sure what you mean.
Last night, I got the front and back to a ps2 model with the obj dump, but the same poses are in different frames when ripped. The character is Janus Cascade (Human)
I've never heard of a model being split between front and back. If the front and back seem to match up, you should be able to combine the two meshes (so that they can be selected as one), and then merge the vertices.
It would help if you can upload a screenshot.
It's funny because I posted a thread in the spam zone about it.
You're saying those two meshes aren't attached?
I found a video that tells you how to do what I said in 3DS Max: