Without the disc image? No. The source port installer requires it. However, if you own the GoG version of Syndicate Wars, you already have the disc image.
It's hidden in the "SWARS" game folder in BIN/CUE format. Simply rename "game.ins" to "game.cue" and mount it using virtual drive software (WinCDEmu, DAEMON Tools or whatever you prefer).
The source port installer should work fine.
Note - the disc image does come with the music tracks, but some virtual drive software - specifically WinCDEmu - won't emulate it, so you can't install the music. You may have to acquire the music somewhere else, convert it to OGG and put it in the appropriate folder.
Hope this helps :)
Post edited May 08, 2020 by mrelusive603