>> John Giant Clay wasn't 76 years old when he died. In the Meg 216 Clay as an old man reminicises about the time he spent with the Harlem Heroes 75 years previously. He must be at least one hundred when he dies.
>> HH takes place in 2050ish and presumably Giant was in his late 20's you can place his birth around 2025 or just before. So he's 74ish when Giant graduates, and pushing a 100 when he throws his last airstrike.
Most people assume that HARLEM HEROES is set in 2050 but it's just as likely it takes place in 2077. If their induction/graduation dates are anything to go by, Judge Giant senior was born c. 2079, his son Judge Giant junior was born c.2105.
The dates given in the first series of HARLEM HEROES are inconsistent. Prog 1 merely states that aeroball "has swept the world" by 2050, not that the story takes place at that particular year. When it was first published, 2000 AD's stories were often set one hundred years from the cover date. Furthermore, Giant's supposed tomb [INFERNO (Prog 72)] has the following inscription:
IN FOND MEMORY OF
JOHN 'GIANT' CLAY
2150 - 2178
DESTROYED IN HIS PRIME BY THE
HARLEM HELLCATS
R.I.P.
Assuming the above dates are typos and INFERNO (its early episodes stating the action is taking place during the 21st century) is set in 2078, this would make Giant senior twenty-nine years old when he fathers Giant junior [JUDGE DREDD 'The Academy of Law (Progs 27 - 28)]. Giant is therefore seventy-six when he dies in 2126 [WHATEVER HAPPENED TO . . . 'John "Giant" Clay?' (Meg 216)].