Marvel stories involving time-travel to the Silver Age or Bronze Age

[Gaastra]

Spider-girl vol 1 issues 10 and 11 had spider-girl go back in time to the main marvel universe and meet a young Spider-Man and torch!

[marshal88]

iron man 150 and 250 - doomquest i and ii

[DrNewGod]

Avengers Annual 2 had the then-current Avengers fighting with the original team. One of my favorite Annuals of all time. First appearance of the Scarlet Centurion.

That was more a time-sideways thing than what the OP asked for. The "current" Avengers had time travelled to WW2, and returned to a version of their own time where Scarlet Centurion had manipulated the Original Avengers into conquering Earth for him.

[Electricmastro]

Not time travel, though I feel New Avengers (2005) is still worth mentioning.

[The Negative Zone]

That's a different "The Iron Age." The Kurt Busiek one was set in the past, but in the early '10s they did a miniseries where Iron Man travels back in time to earlier Marvel comics eras.

Oh my gosh. I remember this. The really weird storyline where Iron Man time travels and gives generic advice to superheroes in order to stop the Pheonix force