The Mexican comic book covers above all promise Turok will face off against(or at least run away from)various UFO's and their sundry alien inhabitants. The only time I know of that Turok and Andar battled spaceships was in issue #58 of the Gold Key run when they confronted robots from space.
And while we're on the subject. The cover of issue #58 by George Wilson was later altered nad reused on issue #98, but not quite all of it. The alien robots are removed and the dinosaur altered, along with a new caveman victim and his raft.