CHARLESTON – Vin Baker has a new heart that beats regularly. Nazr Mohammed has a new knack of running the floor regularly.

Whether the Knicks’ two centers erase the perception the club’s weakness is in the middle in a conference suddenly boasting Shaquille O’Neal won’t be determined on the operating-room table or in uptempo Charleston scrimmages.

Knicks prez Isiah Thomas spent the summer trying to trade Mohammed in an Erick Dampier sign-and-trade, seeking a center upgrade.

Mohammed, nearly dealt to Golden State, told The Post, “It’s not one of our weakest links. I think we’re strong at the center position, with myself and Vin. I don’t think many people can stop me or play at the level I’ll be playing at this year. I know Vin feels the same way. If they want to underestimate us, we can surprise people.”

Baker is ready to shock the world, just like his heart was “shocked” in a 21/2-hour operation in late June that corrected his arrhythmia that was misdiagnosed for years. “They went through the jugular, up through the groin and went into the heart and shocked it,” Baker said. “I was scared of course, but we got it done.”

“I definitely feel my energy bouncing back very quickly,” Baker said. “I felt like my heart was beating at a rapid pace [on the bench] almost like I’m working out.”

Lenny Wilkens thought Baker’s fatigue was from being out of shape, not knowing about his irregular heartbeat. “His recovery is much better,” Wilkens said. “After you get him going up and down and he gets a break, he gets back to a higher level where last year he’d still be tired.”

However, Mohammed is not ready to give up his starting job to Baker. Mohammed was the better rebounder and low-post defender at Charleston camp that broke yesterday.

Five pounds lighter, Mohammed also surprised Wilkens by getting out in transition. “He’s quicker,” Wilkens said. “[Last season], sometimes he didn’t really get down the floor. I told him that, showed him on video. He needs to learn how to run the floor so he can get easy opportunities. If we’re going to push it, you need to really get down the court, into a low-post position or into the lane where we have a quick opportunity.”

Indeed, this was Camp Perfection. Knick spin doctors Wilkens and Thomas would not admit the team showed any weaknesses in Charleston, other than for its sweet tea. Perhaps they have until January when Shaq gets his first crack at exposing the Knicks.

“Shaq is going to be Shaq wherever he goes,” Knicks assistant Herb Williams said. “We just have to attack at other positions. Shaq is going to get his points.”

Meanwhile, the Baker-Mohammed battle could last all preseason. I want to start just like anyone else in this league,” said Mohammed.