Avengers (1963 1st Series) #167 VF+ [1st Guardians of the Galaxy crossover.]
Published Jan 1978 by Marvel.
The Korvac Saga: Part 1 of 10 - "Tomorrow Dies Today!" Guest-starring the Guardians of the Galaxy. Script by Jim Shooter. Pencils by George Perez. Inks by Pablo Marcos. Cover by George Perez and Terry Austin. The Korvac Saga begins! A sensational storyline that sends Earth's Mightiest Heroes on a ten-issue odyssey to save the universe! The epic adventure begins with a simple distress call from Nick Fury. An enormous spaceship is orbiting the Earth! Where did it come from and who does it belong to? The Avengers blast off in a quinjet to find out! After boarding the giant ship, the Beast bumps into the Guardians of the Galaxy! Why have Charlie-27, Martinex, Nikki, Starhawk, Vance Astro, and Yondu come to the 20th century? It's a long story, that's only just beginning! Meanwhile back in New York City, the Wasp's first fashion show is interrupted by the Porcupine! Fortunately, Nighthawk and Yellowjacket are in attendance to fight the prickly villain! But someone else is present too...a mysterious man named Michael. More will be heard from him later...much more. Avengers Lineup: Beast, Captain America, Iron Man, Scarlet Witch, Thor, Vision, Wasp, Wonder Man, and Yellowjacket. (Notes: Korvac previously appeared in Thor Annual 6. The 10-issue Korvac Saga takes place in Avengers 167-168 and 170-177. Roger Stern is also credited with scripting this issue.) Cover price $0.35.