Corey Feldman -- This One Goes Out to Corey Haim (AUDIO)

It took him 5 years, but Corey Feldman is finally ready to honor his BFF Corey Haim in song -- recording a tribute to him to mark the upcoming anniversary of his death.

The song is called "Remember 222" and will be released March 10th. Haim died in 2010 from pneumonia and a bad heart.

The title refers to Haim's favorite number -- which, as Feldman has pointed out for years ... is eerily similar to his own fave digits ... 22.

Interestingly, the lyrics make reference to the Coreys' drug history: "Made the most of every day ... we altered our reality." It also features dialogue from some of their movies ... like "The Lost Boys," and "Dream a Little Dream."

It ain't "I'll Be Missing You" ... but it's the thought that counts.