Is it possible to mod a traditional sofa into a sofa bed?

I have a traditional couch and a pull out couch (sofa bed). Both are great, but the traditional couch is more comfortable. Can I take the internal part that is the sofa bed and put it into the frame of the other couch? Anyone have any suggestions on how I can do it if that's possible?

Comments

[Re-design]

If they are close in size you might be able to do this.

But in my experience what makes a sofa bed uncomfortable is the part that make is a sofa bed.  You give up spring and padding space for the mechanics of the pull out part.

So in the end you might be turning a comfortable sofa into a less comfortable sofa bed.