The IMSA WeatherTech SportsCar Championship field will take to Watkins Glen International next weekend for the annual Sahlen’s Six Hours of The Glen, as the Tequila Patrón North American Endurance Cup gets back underway.

Thirty-nine cars will take part in the race, the first time all four categories have competed together since the Circuit of The Americas round in early May.

ENTRY LIST: Sahlen’s Six Hours of The Glen

The headline Prototype class will consist of the ten full-season entries, with Rebellion Racing having previously announced it would skip the Watkins Glen TPNAEC round.

Ford Chip Ganassi Racing regular and Onroak development driver Olivier Pla will replace Tom Kimber-Smith in the PR1/Mathiasen Motorsports Ligier JS P217 Gibson, joining Jose Gutierrez.

It will be one of four two-driver lineups in the class, along with the No. 31 Action Express Racing Cadillac DPi-V.R and championship-leading Wayne Taylor Racing entry, as well as VisitFlorida Racing’s Riley Mk. 30 Gibson.

The Prototype Challenge class is set to increase to four entries with the return of Starworks Motorsport, although its drivers are currently unconfirmed, as are those in the No. 26 BAR1 Motorsports Oreca FLM09.

The absence of Risi Competizione reduces the GT Le Mans class to eight cars, following a heavy shunt for the Houston-based team in last weekend’s 24 Hours of Le Mans.

This leaves two cars apiece from Corvette Racing, BMW Team RLL, Ford Chip Ganassi Racing and Porsche GT Team, all with two-driver lineups.

Once again the largest category is GT Daytona, making up almost half the grid at 17 cars. Two cars have joined the field since Detroit.

Alex Job Racing returns with its Audi R8 LMS driven by Bill Sweedler, Townsend Bell and Frankie Montecalvo, while Dream Racing rounds out the grid with its Lamborghini Huracan GT3 for Lawrence DeGeorge, Paolo Ruberti and Cedric Sbirrazzuoli.

The race will be broadcast on FOX Sports 1 and FOX Sports 2, while streamed in its entirety on the FOX Sports GO app.

Track action will start on Friday, June 30, with the race at 10:10 a.m. ET on Sunday, July 2.