You're most likely thinking of the retroclone FASERIP, named after the fan-created nickname for Marvel Super Heroes as an acronym of its PCs' stats. It's well-known and -liked by fans of old-school supers. This is a fairly straightforward retroclone, intended to be Marvel Super Heroes in all but name.
Less likely, you might instead be thinking of the less-well-known Four Color System, another retroclone of Marvel Super Heroes. This takes more of a toolkit approach to the original rules, so it's more flexible, but not as immediately playable right out of the box. It's regarded as a useful reference if you're already playing MSH, and as a resource for hacking on the original MSHRPG and other FASERIP games.