Colin Chapman's monocoque Lotus 25 of had put the writing on the wall for older spaceframe chassis designs, and most other Formula One constructors hurriedly started work on their own monocoque cars.
The engine's internals remained almost unaltered from the Peter Berthon-designed unit which was installed in the V8 version of the P57, the BRM P578, with which Graham Hill had won the World Championship in .