AUBURN HILLS, MICH. ? Pat Riley’s experiment is about to be put to the test.

The Miami Heat president shook up his team after it fell just short of beating the Detroit Pistons last year in Game 7 of the Eastern Conference finals. Then Riley became coach of his new-look team after Stan Van Gundy resigned for family reasons.

If the Heat can get past the Pistons in this year’s conference finals, which begin tonight in suburban Detroit, Riley’s revamping of Shaquille O’Neal and Dwyane Wade’s surrounding cast will be deemed a success.

If not, even Riley acknowledges the moves will have failed – and says he might revise his roster again this offseason.

The Pistons, who had to rally from a 3-2 deficit and escaped Miami with a tight victory to advance to their second straight NBA Finals a year ago, raised their eyebrows when Riley changed much of his roster.

“I was surprised, especially with them being so close to making the finals, not trying it out again, to see what would happen,” Detroit point guard Chauncey Billups said. “They made their adjustments to make sure they beat us.”

Hours after signing O’Neal to a $100 million, five-year deal in August to keep him paired with Wade, Riley engineered the largest trade in NBA history.

Miami acquired forwards Antoine Walker and James Posey along with point guard Jason Williams in a five-team, 13-player trade that dealt small forward Eddie Jones to Memphis.

Riley also signed point guard Gary Payton, let go of role players Keyon Dooling and Rasual Butler, and acquired shooting guard Derek Anderson in a midseason trade.

A year after both Wade and O’Neal battled injuries in a grueling seven-game series, the Heat are healthy and rested this time after eliminating New Jersey last Tuesday.

“We always had an excuse about last year,” Riley said. “We had guys hurt, we had too much time off … And so there was always an excuse. There’s none now.”

While Riley was shaking up his roster, Joe Dumars was keeping his nucleus together.

The Pistons president of basketball operations brought back his top seven players from last year – when they almost repeated as NBA champions – and added Dale Davis, Maurice Evans and Tony Delk, although those reserves saw little playing time.

One of the most resilient teams in sports was down again heading to Game 6 in the second round against LeBron James and the Cleveland Cavaliers, winning a series after facing a 3-2 deficit for the fourth time in four postseasons.

“What we went through in the last series pretty much sums up the last three years for us,” Richard Hamilton said.

O’Neal hopes he’s not saying the same thing soon.

Detroit has eliminated O’Neal-led teams the past two years: Miami last year, and the Los Angeles Lakers in the 2004 NBA Finals.