The opportunity to win an NBA title for even the most talented squad comes in certain windows.

Teams usually have one, two or three seasons at the most to take advantage of those opportunities.

The 76ers’ window to win a title opened a few seasons ago with young standouts in Joel Embiid, 24, and Ben Simmons, 22.

Embiid was voted an All-Star Game starter for the second consecutive season. Simmons, meanwhile, was named an All-Star reserve.

“So the window is now,” general manager Elton Brand said. “The opportunity is now.

“So once I saw that [Embiid and Simmons improved over the summer], we discussed taking a shot at it now, because who knows how long that window is going to be open?”

That’s why the Sixers reshaped their roster before Thursday’s 3 p.m. trade deadline. And they’ll make some more moves if a desired player becomes a free agent in the buyout market.

But the 2017 first-overall pick Markelle Fultz along with Wilson Chandler, Landry Shamet and Mike Muscala were all traded during a two-day frenzy that began in the wee hours of Wednesday morning. They were replaced by fringe All-Star talent Tobias Harris and Boban Marjanovic, Mike Scott, James Ennis and Jonathon Simmons in moves that elevated the Sixers into an Eastern Conference title contender.

“We believe we are in a position to contend now,” Brand said. “And our moves reflect that.”

But the moves came at a price.

In order to get Harris, Marjanovic and Scott from the Los Angeles Clippers on Wednesday the Sixers gave up Shamet, Chandler and Muscala in addition to four draft picks — a protected 2020 first-rounder, the Miami Heat’s 2021 first-rounder, a Detroit Pistons 2021 second-rounder, and the Pistons’ 2023 second-rounder.

But they believe the draft picks don’t compare to what Harris provides.

The Sixers feel he complements and strengthens the core group they already had in Embiid, Simmons, and Jimmy Butler.

Add JJ Redick to the mix, the Sixers now have the league’s second-best starting lineup behind the Golden State Warriors.

“We had to add a player like that when we had the opportunity,” Brand said of Harris. “We had targeted him as a player we would want if he became available. We coveted him.

“We know he fits great into our system, and he’ll do well.”

The Sixers plan to keep the core group intact no matter the price.

They’ll most likely have to sign Butler and Harris to max contracts next summer to make that possible. Harris is in the final year of his contract. He’ll become an unrestricted free agent on July 1. Meanwhile, Butler can opt out of the final year — 2019-20 — of his contract this summer to become a free agent.

Simmons is also scheduled to sign a max extension before next season.

Brand said the Sixers ownership group is committed to keep the team together.

“I’ve gotten assurances from the managing partners that we can bring them back and sign them for what we need to sign them for,” Brand said. “A lot of things need to happen before that. But we are all on board to keep this core together a long time.”

Meanwhile, the Sixers apparently got tired of waiting on Fultz.

Raymond Brothers, Fultz’s agent, announced on Dec. 4 that Fultz had been diagnosed with thoracic outlet syndrome. Brothers said that the condition was the reason for the guard’s shooting woes and that his client would remain sidelined at least three to six weeks. However, Fultz hasn’t played since Nov. 19.

“You know the goal then, we expected him to be back at some time this season,” Brand said. “That was our hope. Right now, we had a chance to add a player, wing depth. We had to go do it now.”

But his being sidelined because of his shooting woes is nothing new. Fultz actually missed 103 games as a Sixer, dating back to last season.

So why now? His trade value was higher last summer. They likely would have been better off trading him at that time.

“Just where we are in the season integrating him in a month or so when we were hoping he’d come back in two or three weeks whenever that was,” Brand said. “To add a piece now, get ready for the playoffs and to get some assets, a first-round pick and a second-round pick, it just felt like the time to do it now.”

However, it appears the team tired of all the drama. Fultz looked bad, with conflicting statements about his health dominating media reports off the court and his poor production got full attention on the court.

By moving him, the Sixers will avoid having to pay the $9.7 million that Fultz is guaranteed for next season.

But the moves raised the bar this season.

“I’d be disappointed for sure if we don’t get to the Eastern Conference Finals and do well,” Brand said.