I wished I remembered more. The front cover was a rather cool looking spaceship, in the novel it may have fired torpedoes. I was very young and don’t recall the story at all. Any help would be much appreciated.
This is a long shot given such little information, but I'm going to suggest as a possibility either 'The Cyborg and the Sorcerers' or 'The Wizard and the War Machine', both by Lawrence Watt-Evans. They were published in 1982 and 1987, respectively, and the latter is the sequel to the former.
According to Google, both have been reprinted with several different covers, so whether or not they have a 'cool looking ship' depends on the which cover you're looking at.