Synopsis
The 1st story reprints Avengers #3 where Hulk and Sub-Mariner teamed up against the team.
Story 2:- Crack in the armour
Giant-Man and Iron Man are sparring in an automobile graveyard. IM's in his 1st slimline red & gold armour and GM claims to have learned how to grow even bigger. GM prepares to throw a car at IM who responds with improved repulsor rays. GM slams down 2 halves of the car but IM speeds out of the way on roller skates in his boots. IM then sets fire to the seat of GM's pants and then knocks him down. GM cries uncle and then shrinks down to human size.
They ride back to Avengers Mansion in Tony Stark's limousine (and the driver's presumably Happy Hogan). En route GM wonders why they keep upgrading their powers. IM went from bulky grey armour to bulky yellow armour to the current 1, and keeps adding facilities. He himself went from Ant-Man to Giant-Man and he figures he might invent another super-id if necessary. But he still thinks he and even IM aren't in the same weight-class as Thor, Hulk and Sub-Mariner. He asks what if it's not enough and 1 day they fail?
IM says they'll rise to whatever challenge comes along. GM snorts that it's easy enough for a billionaire like him to say. IM tries to continue the fiction that he's just Tony Stark's bodyguard, but GM says he can't fool the 2nd smartest man in the world after Reed Richards. IM insists he's wrong and GM agrees to continue pretending.
They arrive at the Mansion in time for a team meeting. GM gets out but IM elects to stay behind for a minute. When he's alone Tony Stark takes off the armour's faceplate and has a drink to fortify himself.