Transition is the word for the 2013 season as American Le Mans Series manufacturers and teams prepare for the merger of the ALMS and GRAND-AM series and unified classes and events for 2014. One group expected to remain virtually untouched is the current GT class of ALMS, where top manufacturers, teams and drivers have delivered some of the best competition in the world. If it is not broken, why fix it?

Still, change is the one constant in racing and the GT field gathered here at Sebring reflects change as well.

The defending ALMS GT champions from Corvette Racing will rely on the proven Corvette C6.R-Michelin combination for champions Oliver Gavin and Tommy Milner and teammates Jan Magnussen and Antonio Garcia in 2013, while Corvette develops the exciting new seventh-generation Corvette Stingray-based race car for 2014 competition.

Taking a different route, the defending Sebring GT champions from BMW Team RLL, present a spanking new pair of V8 powered BMW Z4 GTEs and a switch to MICHELIN^® tires for 2013. Joining Bill Auberlen and Dirk Müller will be Maxime Martin, John Edwards and Joey Hand.

A highly anticipated change for Sebring fans arrives in the form of a potent pair of cars from the SRT Motorsports Viper factory team returning to Sebring after a 12-year hiatus. The Riley-prepared Vipers entered four ALMS rounds in 2012 in preparation for a championship attack in 2013 with a driver line-up featuring Dominik Farnbacher, Kuno Wittmer, Marc Goossens, Jonathan Bomarito, Ryan Dalziel and Tommy Kendall.

One the most successful teams in international sports car competition returns for the 2013 season. The Risi Competizione Ferrari with former Viper and Corvette ace Olivier Beretta and Matteo Malucelli is back after a one-year hiatus. Risi once again teams with Michelin as it seeks its fourth Sebring GT victory since 2007.

Shock waves rolled through the blogosphere last month when the 2012 ALMS GT runner-up and Petit Le Mans winning Extreme Speed Motorsports Ferrari team announced an immediate switch to the P2 class beginning here at Sebring with a pair of HPD-Honda prototypes. But the Ferrari banner has been seized by Alex Job Racing as the ultra-successful team joins with West Racing, Yokohama and drivers Townsend Bell and Bill Sweedler.

Another big surprise saw the Flying Lizard Motorsports Porsche team step down to GTC class competition, but Porsche loyalists fear not as the Derrick Walker-led Falken Porsche, with Bryan Sellers and factory man Wolf Henzler, continues an aggressive development program and Paul Miller Racing moves to Michelin with Marco Holzer joining Bryce Miller aboard.

Meanwhile, the double-defending PC champion CORE autosport team picks up the FLM equipe’ and expects to enter the ALMS GT fray at Monterey with Patrick Long, Tom Kimber-Smith and Michelin.

Adding to the GT field will be two factory Aston Martins with Stefan Mucke, Darren Turner, Bruno Senna aboard the #97 and Dane Cameron, Paul Dalla Lana and Billy Johnson in the #007. Aston Martin Racing last won at Sebring in 2005 and won the pole last year at Mazda Raceway Laguna Seca.

The GT field here at Sebring is due to include eight top teams from six different manufacturers and three tire makers. That includes factory pairs of Chevrolet Corvettes, SRT Vipers, new BMW Z4s and Aston Martin Vantage GTEs to take on top independent Ferraris from Risi and AJR and Porsches from Walker and Miller.

Race fans and industry insiders recognize that factory and top independent teams come to Sebring with the fullest possible array of resources. That means top drivers and the best technical boffins, strategists and crews; aggressive R&D and testing, and an uncompromising approach to an important and highly prestigious race.

Is it any wonder that media, race fans and manufacturers consider this the best racing on the planet? That is one thing not about to change.