GTA chairman Masaaki Bandoh revealed the plans in his regular press conference ahead of this weekend's season finale at Motegi on Saturday.
SUPER GT brought in a new 450km race format last year, with one race each at Fuji and Suzuka being run to the longer distance instead of the regular 300km length.
For the 2023 season, 450km became the default distance, with Autopolis using the format for the first time and only the races at Okayama, Sugo and Motegi staying at 300km.
Next year's schedule was revealed back in August, featuring the same venues as this year, with plans to revive an overseas round coming to nothing due to cost grounds.
But Bandoh said there will be more variation in terms of race distances and lengths, with plans for a timed race, first mooted ahead of the 2022 season, back on the agenda.
While he wouldn't be drawn on the exact make-up of the schedule, he revealed that a timed race would be held to three hours.
If a 300-mile race is implemented, it would be the first time SUPER GT has run a race using miles instead of kilometres since the 2019 season, when Fuji held a 500-mile race.
At around 480km, it would be slightly longer than the 450km format, although shorter than the 500km length that used to be a regular feature of the SUPER GT schedule and was last used in 2021.
Fuji and Suzuka appear to be the most likely candidates for the new formats be used, especially with both venues set to again host two races apiece in 2024. Bandoh previously has spoken of making the August Suzuka race a timed event.
Six cars for GT300 carbon-neutral test
A test for GT300 cars will be held following Sunday's finale at Motegi on Monday with the new 50 percent renewable fuel that is planned to be introduced for the 2024 season.
However, just six cars will participate in the test, of which just one is a FIA GT3 car, with the remainder being GTA-GT300 ('JAF') cars.
The participating cars are: the #2 Inging Toyota GR86 GT, the #30 apr Toyota GR86 GT, the #31 apr Lexus LC500h, the #52 Saitama Toyopet Toyota GR Supra, the #61 R&D Sport Subaru BRZ and the #65 LEON Racing Mercedes-AMG GT3.
It remains to be seen whether the new fuel will be implemented for 2024, with a final decision to be made in consultation with the teams after Monday's test.
The GT500 class will continue to run with the 100 percent renewable fuel that was brought in for this season.
Motorsport.tv is showing all qualifying sessions and races for the 2023 SUPER GT season. For more information, click here.
