Oh, SsssssSly

It’s official: After buzzing the lists of pending sequels since 1986--and the release of the original venomous creature--”Cobra II” is threatening!

A rep for Warner Bros. confirms that it’s in development. (The title, as registered with the MPAA: “Cobra II: Head of the Snake.”) The reason may have much to do with worldwide grosses of more than $150 million.

But, wait--a source close to Sly Stallone tells us that he won’t slither back into cop Marion Cobretti’s boots until waaaaay down the road. His probable next film--following “Rambo III”--will be a sci-fier, with Stallone playing a war-weary soldier-of-the-future (whose body bears tattooed numbers of the dates of all his battles). He encounters a newer, younger breed of soldier (“They’re like Dolph Lundgrens” is how Stallone put it to us), as well as the requisite quest.

Plans--at present--are for the pic to shoot in the summer near Chicago.

Meanwhile, “Rambo III” continues its epic shoot. Just returned from Thailand (after starting out in Israel), cast and crew are readying to head to Arizona, where climactic scenes (of Rambo and Trautman and Afghan warriors squaring off against Russkies) will be filmed in a valley encircled by snow-capped mountains.

While we’re talking tough guys: Arnold Schwarzenegger’s been uncharacteristically silent since taking shots at Sly--about everything from his clothes to his jewelry to his attitudes about women--in his recent Playboy interview.

This after hastily going on the air with “Good Morning America’s” Chantal and explaining that he’d been, um, misquoted. (Playboy later countered--and said that what had been said about Sly off-the-record was even more inflammatory.)

This wasn’t the first time a national publication got Arnie’s words on his colleague all jumbled up. In a cover story in a 1986 issue of GQ, Arnie took potshots at--among other things--Sly’s penchant for giving big money to charities, saying it was an attempt to buy respectability.

Sly himself put in a phone call to Arnie on that one. Arnie’s response: He’d been misquoted!

The latest cracks about Sly have made the wires and the tabloids (which ran pics of the two he-men, suggesting a face-off).

But they didn’t prompt the “publicity blackout” that shortly followed on the set of the latest Schwarzenegger pic, “Red Heat,” which Walter Hill is directing around L.A. According to a rep for Schwarzenegger: “It’s just that they’re real busy these days on the set. And Arnold’s trying not to break concentration.”