While an upcoming  DALLAS ep mourns J.R. Ewing, the late LARRY HAGMAN’s co-stars  battle for a slice of Southfork.

Jesse Metcalfe and Josh Henderson are at each other’s throats, battling over which of them will fill Larry Hagman’s cowboy boots now that the beloved actor has died.

Not that producers and writers are set on give Hagman’s legendary character – devious oil tycoon J.R. Ewing – a funeral on the series March 11, both Jesse, 34, and Josh, 31, are jostling to fill the void left after Hagman’s Nov. 23 death at the age of 81.

“Jesse and Josh each want a bigger piece of the action on the show now that Larry’s gone,” said a source close to the production. “Both of them loved Larry, but that hasn’t stopped them from lobbying hard to have their story lines expanded now that he’s not around anymore.”

Not long after Hagman’s passing, Jesse – who plays J.R.’s adopted nephew Christopher Ewing on the reboot of the nighttime soap – was quick to go public with a statement about the actor.

“It was truly an honor to share the screen with Mr. Larry Hagman,” he said. “With piercing wit and undeniable charm, he brought to life one of the most legendary television characters of all time. But to know the man, however briefly, was to know a passion and dedication for life and acting that was profoundly inspirational.”

The source added: “Jesse wanted to work quickly to get his name out there.”

But Josh, who plays J.R.’s son, John Ross, on the show, thinks he’s got the inside track to take over, the source noted.

As The ENQUIRER reported in our July 2 issue, the onscreen rivals mix like Texas oil and water when the cameras stop rolling. But that was no surprise to many – they’d long competed for the same roles in auditions.

“Jesse and Josh have had a competitive, sometimes even hostile, relationship for years,” the source added. “There’s a lot of bad blood there – and now it looks like it’s going to get even worse.”