Competing against a field that included multiple turbo-charged Ford Sierras, Grice and Percy prevailed to record a famous victory in a Holden VL Commodore SS Group A SV.

In 1974 Grice began driving for the Craven Mild Racing team and the following year he won a number of rounds in the Australian Touring Car Championship in his SL/R 5000 Torana.

In round five, at Surfers Paradise, Grice won the race but was disqualified following a protest lodged by Holden Dealer Team manager Harry Firth.

Firth correctly contended that the thermostat from the Holden V8 engine in Grice's Craven Mild Torana L34 was in fact in the car's glovebox and not where it should have been.

In 1978 Grice broke through with a placing in the Bathurst 1000 when he came second behind Peter Brock in a Craven Mild Racing Holden LX Torana A9X SS5000.

After contemplating giving away racing, with no prospects of a competitive drive, Grice was thrown a lifeline by Re-Car owner Alan Browne.

Grice easily won the 1984 Australian GT Championship driving the ex-Bob Jane DeKon Chevrolet Monza that had been acquired by Re-Car boss Alan Browne.

In late 1984 Grice was joined by fellow touring car star Johnson and driver-engineer Ron Harrop in the Monza, when they contested the Sandown 1000 as part of the 1984 World Endurance Championship.

The Monza ran strongly, with Grice reporting that the 600 bhp (447 kW; 608 PS) 6.0 L Chevrolet was able to stay with the faster Porsches on the straights, but lost out to the ground effect sports cars through the turns (Johnson claimed that the car had a lot more grunt than its handling deserved, though Grice contended that the Monza handled very well).

Driving a Charles Ivey Racing prepared Porsche 956, with co-drivers Alain de Cadenet and Chris Craft, the car was qualified 32nd, but was a DNF with engine failure after 274 laps.

Grice, who proved the fastest of the trio despite never having raced at Le Mans or in a 956, was openly critical of the team and their preparation of the car which had a bad habit of losing wheels at high speed.

In 1990, Grice and his old Roadways touring car team led by team boss and chief mechanic Les Small, developed a left-hand-drive Holden VN Commodore powered by a 358 cubic inch Chevrolet V8 engine to run in the Australian NASCAR series, with Grice taking several wins at both the Thunderdome and the 1/2 mile Speedway Super Bowl at the Adelaide International Raceway.

In 1988, thanks to his friendship with his 1987 James Hardie 1000 co-driver Percy, Grice was drafted into the Nissan Motorsport Europe team for the European Touring Car Championship, driving a Nissan Skyline HR31 GTS-R. Percy, Grice, and Swedish driver Anders Olofsson, drove the car to sixth outright in the 1988 Spa 24 Hours.

Grice also won the inaugural Bathurst 12 Hour held in 1991 driving a Toyota Supra Turbo with Peter Fitzgerald and Nigel Arkell.

Grice continued to compete as an endurance co-driver, his last appearance was at the 2002 Bathurst 1000 driving a Ford AU Falcon entered by V8 Ute series team Nilsson Motorsport.