Are All Might and Midoriya equally strong when they use One for All 100%? Even though Midoriya can't use One for All without breaking his body, if both Midoriya and All Might use One for All 100% in their primes, are they supposed to be equally strong? Does their particular body influence how much strong each one are or by having One for All they are about the same? Does the manga give some light about this?
As @Ero Sɘnnin stated OfA stockpiles however with the latest chapters of manga we have to consider one more thing.

Manga spoilers:


   In the latest chapters in his dream, Izuku sees the first user of OfA, brother of AfO user, and some event that happened at that era. However at the end first user of OfA talks with Izuku. That never happened to All Might and this is stated in anime and manga. After waking up his hands starts to glow. I think that was a power-up so he is definitely becoming stronger and will suppress All Might.


Not the mention of he calling himself "Greatest hero" in the first episode.