What GA comic book characters would make good pulp characters, heroes and villains, both? An obvious example would be the Bat-Man. With a tweak here and there, he'd make a great pulp hero (and already had a pulp equivalent, of sorts, with Black Book Detective's "The Black Bat").
Some other good candidates are Sandman (the original gas-masked version), The Blackhawks, The Vigilante, and The Spirit. I'd include characters like Slam Bradley, but they're already close enough to pulp characters that there's not much point in mentioning them, at least not so far as I can tell.
Any other nominations?