The head sculpt with long hair on the new Endgame 6" Basic Captain Marvel that comes in the 2-Pack. The Binary version fits perfectly on the Captain Marvel Walmart exclusive Binary figure if you prefer the longer hair endgame look. It would fit on the regular ML Captain Marvel figure as well but it does have the translucent hair. There is a single packed Endgame Captain Marvel Basic figure with non-translucent hair as well which should figure on the Marvel Legends figure as well. I don't have that one though and prefer the Binary look.

Also as a side note the Hasbro basic 6" Quantum Suit Rocket Racoon will fit in pretty well with your Marvel Legends. It's not as articulated as the Marvel Legends Rockets but who know's if or when Hasbro will make a ML version.

Very cool little headswap there.  I'm gonna pick up the Rocket as well!

Good call!  Any QS rocket is better than none at this point.  

Looks  surprisingly good, I even think that this basic head has more accurate shape of Brie Larson's head than legends version.