However IMSA GTP regulations differed from Group C and subsequently the 956 was banned in the US series on safety grounds as the driver's feet were ahead of the front axle center line.

To make the 956 eligible under the new IMSA regulations, Porsche extended the 956's wheelbase to move the front wheels ahead of the pedal box.

The newer Andial built 3.2L fuel injected flat-6 would be placed in the 962 by the middle of 1985 for IMSA GT, which made the car more competitive against Jaguar.

Due to the high demand for 962 parts, some aluminium chassis were built by Fabcar in the United States before being shipped to Germany for completion.

Derek Bell, a 5-time Le Mans winner, drove the 962 to 21 victories between 1985 and 1987, remarked that it was "a fabulous car, but considering how thorough Norbert Singer (the designer of the 962 and head of Porsche's motorsport division at the time) and the team were, it was really quite easy to drive.

John Thompson designed a chassis for Brun Motorsport, eight of which were built and helped the team take second in the World Sportscar Championship in 1987.

Richard Lloyd Racing's GTI Engineering would turn to Peter Stevens and Nigel Stroud to develop five 962C GTis, which featured entirely revised aero and aluminium honeycomb rather than sheet tubs.

In the United States, the ball got rolling when Holbert Racing began making modifications to their own chassis and rebadging them with "962 HR-" serial numbers.

Porsche debuted the 962 at the 1984 24 Hours of Daytona with Mario and Michael Andretti driving the factory car which led the race until it retired during lap 127 with engine and gearbox problems.

The car, driven by Henn, Michel Ferté and Edgar Dören, was classified in 26th position despite their race ending after 247 laps with ignition failure.

After a post-'87 "dry spell", Porsche customer Jochen Dauer got the 962 re-classified as a road legal GT1 car under a loophole in the new ACO regulations for the 1994 24 Hours of Le Mans.

The 962 also won the 24 Hours of Le Mans in 1986 and 1987, with Derek Bell, Al Holbert and Hans-Joachim Stuck at the wheel on both occasions, as well as later winning under the Dauer 962 badge in 1994.

The presence of strong factory teams, such as Jaguar, Mercedes-Benz, Nissan, and Toyota, competing against privateer 962s eventually led to the car becoming less successful in the later 1980s.

German tuner DP Motorsports completed a road conversion in 1992, with a total of three cars, known as DP62s, built upon existing 962 racing chassis.

The bodywork and chassis were completely new and unique, designed by Mike Simcoe of GM Holden in Australia, but the engine was taken directly from 962s, although it was also expanded to 3.3 litres.

A run of Derek Bell edition 962 road cars was planned, but only one was completed, powered by a 580 bhp (430 kW) engine from the 993 GT2.