After taking victory yesterday, the duo went back-to-back in the brand new GT4 Mustang, the only one of its kind in Australia.
In second position came the Method McLaren of Tom Hayman and Marcos Flack, but it could have been much more.
Hayman challenged Gray in the opening stint of the race and was never more than 1s behind, he and Flack had five seconds less stationary time to serve in the stop, however the team did not complete the minimum pit-stop time.
As a result, they were dealt a drive-through penalty which dropped them 18s behind the Miedecke Mustang.
As a solo driver Jake Camilleri drove faultlessly in his Mercedes-AMG GT4 to round out the top three positions.
Australian Production car veteran Tim Leahey came home in fourth position overall and in doing so also won the Am Cup.
Nathan Morcom and Jesse Bryan in the second Method Motorsport McLaren like their teammates were also handed a drive-through for not serving the minimum pitstop time, this dropped them from a podium fight to sixth. Morcom recovered to fifth.
Sam Brabham overtook two-time Bathurst 1000 winner John Bowe in the closing laps to finish in sixth place alongside Bailey Love.
Bowe and Jacob Lawrence finished just 0.9s behind in seventh ahead of Pro-Am class winners Josh Buchan and Jason Yu.
Shane Smollen sat in fourth early on when his rear bumper started to deteriorate and was forced to repair the car. He rejoined at the back, he and teammate Lachlan Mineeff recovered to finish in ninth ahead of Zoe Woods and Daniel Stutterd.
Mark Griffith was 11th from Vince Gucciardo, and the the BMW M4 of Jamie Augustine and Peter Lawrence.
Eddie Maguire served a drive-through and came home in 14th alongside Ben Newman, Jarrod Hughes and Mark Cotterall were the final finishers.
Tony Quinn and Steve Jakic came to blows at Miller corner and both retired as a result.