THE killer Bs are here – an amazing colle tion of 70 low-budget films noir from the 1940s and ’50s un spooling at Film Forum.

The fest includes the usual suspects (“Detour,” “D.O.A” and “Gun Crazy”) as well as obscurities like Joseph Losey’s “M” (1951), a Los Angeles-based remake of Fritz Lang’s German classic, with David Wayne in the role that made Peter Lorre a star.

“It’s very hard to see,” Bruce Goldstein, the Forum’s director of repertory programming, says of the Losey flick. “There’s a rights issue. I had to clear it through the son of the screenwriter, and we got the print from England.”

“As a programmer you’re faced with all this stuff being available on DVD. So I wanted to do a series with things that aren’t so readily available,” Goldstein adds. “We checked it pretty closely, and 40 of the films aren’t on DVD.”

But even if you can watch these flicks at home, they’re best viewed in a theater with an audience of like-minded buffs.

Goldstein speaks highly of Lew Landers’ “Man in the Dark” (1953), a gangster yarn starring Edmond O’Brien – Goldstein calls him “the king of B noirs” – and lensed in 3-D (!) by Floyd Crosby, rocker David Crosby’s father.

“Floyd Crosby is one of the great cinematographers,” Goldstein gushes. “He shot ‘High Noon’ and this is one of the few 3-Ds in black and white. It’s really terrific. I love it.”

“Man in the Dark” is one of five O’Brien starrers in the series, and is on a double bill with Rudolph Mate’s “D.O.A” (1950), in which a dying CPA (O’Brien) has just hours to find the person who slipped him poison.

The San Francisco location shots – a drugstore shootout among them – are amazing.

“Side Street” (1949) – one of seven entries directed by the great Anthony Mann – features terrific New York location lensing, including a chase in the canyons of lower Manhattan and a bit inside Marie’s Crisis, a dingy piano bar on Grove Street in the West Village that stands to this day.

Says Goldstein: “They go inside the bar, and Marie is there!”

How’s that for trivia.

The festival runs through June 15 at Film Forum (Houston Street, west of Sixth Avenue). The complete sked is at filmforum.org

V.A. Musetto is film editor of The Post. He can be e-mailed at vam@nypost.com