BEFORE he squealed about him to the feds, notorious hitman and stool pigeon Sammy “The Bull” Gravano was ready to rub out Mafia boss John Gotti — after the “Teflon Don” double-crossed him with plans to rat him out to authorities!

In his first video interview since a 1997 chat with ABC’s Diane Sawyer, the 74-year-old thug — who put Gotti away by singing to the FBI — revealed the murder plans he’d hatched before he flipped and tied his old godfather to a slew of slayings.

“Here’s my best f**king friend, my boss,’’ he says of Gotti, who got a life sentence and died in the slammer at 61 of throat cancer in 2002.

Read the latest issue of GLOBE Magazine and read this exclusive interview available only in GLOBE Magazine.