2023 Sahlen's Six Hours of The Glen

The Corvette and Lexus also received horsepower increases following adjustments to the size of the cars' air restrictors.

On June 14, 2023, IMSA released the latest technical bulletin outlining BoP for the GTP class.

[10] After missing Sebring, Andrea Caldarelli returned to Iron Lynx's GTD Pro lineup alongside Jordan Pepper.

61 Ferrari 296 GT3 entered, with drivers Miguel Molina, Ulysse de Pauw, and Simon Mann.

[13] The first practice session took place at 4:30 pm ET on Friday and ended with Colin Braun topping the charts for Meyer Shank Racing with Curb-Agajanian, with a lap time of 1:33.563.

[14] The second and final practice session took place at 8:00 am ET on Saturday and ended with Colin Braun topping the charts for Meyer Shank Racing with Curb-Agajanian, with a lap time of 1:32.311.

78 Forte Racing powered by US RaceTronics entry driven by Loris Spinelli set the fastest time among all GTD cars.

Steven Thomas and Gar Robinson were handed pole position for LMP2 and LMP3, respectively after the session did not reach minimum time to be declared official after cars aquaplaned off the track.

30 Jr III Motorsports entry, spun into the inside wall of turn 7 before stopping alongside the tire barriers.

Nick Tandy was handed pole position after the session was cancelled due to poor weather conditions.

[23] Burdon, Fraga, and Robinson extended their advantage in the LMP3 Drivers' Championship over Boyd, Mantella, and Varrone to 124 points.

[23] In the GTD Pro Drivers' Championship, Barnicoat and Hawksworth extended their lead to 113 points over Gounon and Juncadella while García and Taylor moved from third after being fourth coming into Watkins Glen.

[23] The result kept Sellers and Snow atop the GTD Drivers' Championship while Montecalvo and Telitz advanced from fourth to second.