A field of 33 cars will hit the Indianapolis Motor Speedway on Saturday, but with a twist.

The Indy Legends Pro-Am, the spotlight event of the four-day Sportscar Vintage Racing Association’s Brickyard Vintage Racing Invitational, will feature 33 former Indianapolis 500 drivers paired with amateurs for a 50-minute race on the 2.439-mile IMS road course. The green flag is scheduled for 1:35 p.m.

The list of drivers includes two-time “500” winner Al Unser Jr., Davey Hamilton, Max Papis, Willy T. Ribbs and Lyn St. James, all competing in 1960s-era American “muscle” cars. The range of “500” history stretches from Dick Simon, who first raced in 1970, to 2011 starter Alex Lloyd.

“It’s kind of a cliche phrase for all of us now, but every time we come under the tunnel and look at this place, it’s like religious,” four-time top-10 “500” finisher Eliseo Salazar said. “Me and some of the other guys have raced Formula One, Le Mans, World Rally, Dakar, there’s nothing like this place. I’ve said it many times and it’s going to be the case again (Saturday).”

To quantify the field in another way, there are 288 living Indianapolis 500 drivers and more than 10 percent of those are represented in the Indy Legends Pro-Am.

“When we come to the Indy 500, of course, we have a lot of pressure on us,” two-time “500” starter Eric Bachelart said. “So here this is all about fun, you know. It’s fun to do Indy, but doing this, it’s even more fun.”

Also on hand as Honorary Stewards are Tom Sneva, the 1983 “500” winner, and Janet Guthrie, the first woman to start in an Indianapolis 500.

“They do such a fabulous job here with these hundreds of cars and things go more smoothly than you could possibly believe,” Guthrie said. “It’s a fabulous event.”

Unser Jr. won the inaugural Indy Legends Pro-Am last year with his amateur partner Peter Klutt, while Salazar (with Gary Moore) and two-time “500” starter Ribbs (with Ed Sevadjian) rounded out the podium.

Three members of the Unser family will race in the Pro-Am – Al Jr., Robby and Johnny – and then four-time winner Al and three-time winner Bobby will hit the track in vintage Indy cars at 12:35 p.m. on Sunday for an exhibition on the oval. It will be the first time five Unsers have been on track at the same time.

Racing on the IMS road course and exhibition runs on the famed 2.5-mile oval will be virtually non-stop on Saturday and Sunday from 8 a.m.- 6 p.m. In addition, when not on the track, all cars will be on display in the IMS infield providing fans up close access to the cars and their owners.

Twelve different race groups will compete, ranging from early 1900s cars all the way up to modern prototype cars and everything in between. More than 500 cars are on hand for the weekend.

The Indy Vintage Pro-Am drivers will also participate in a Fan Walk through the starting grid prior to the opening ceremonies, allowing fans to see the cars up close, take photos and chat with the drivers.