I want to do a rear brake swap and swap out the rear drum brakes for disk and I was wondering if I couldnt just take a undercarriage from another car that has the same platform, for example, could I take the undercarriage from an Integra?

 

check the stickie at the top of this sub-forum while some of the photo links are broken now, the info in there goes back over 20 years.

 

Quick answer to your question: Yes, you can take the rear trailing arms from i believe 96-2000 integra and basically direct swap them.

Double check the years, as I'm not 100% sure on those, but it's a topic that has been covered dozens of times on the forum.