The DNS-320L and DNS-327L have very different hardware designs from one another. I highly doubt firmware will work across ShareCenter models. Even so, there's a strong likelihood that the DNS-320L will outright reject the DNS-320L firmware as incompatible -- the ShareCenter series have fail safes that prevent accidentally uploading firmware from the wrong model. Even in the off chance that the DNS-327L FW successfully uploaded onto the DNS-320L, do you really want to trust untested firmware on a device designed as a primary repository for your data?