Generally speaking, various compressed archives can be simply repacked between different formats. That means, to extract all the files from the original archive and then compress it to the desired format. In case of multi-volume archives, all pieces are needed of course.
Convert WinACE Compressed ace archive file to Compressed file from a multi-volume archive (part 8).
We found 2 software records in the database related to .ace to .008 file format conversion.
Microsoft Windows software - convert ace to 008 on Windows
Popular open source file archiver with a high compression ratio
Convert from ace file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned ace to 008. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Linux/Unix software - convert ace to 008 on Linux
A Linux application used as frontend for popular compression tools