Part of the deal
Swede Gunnar Nilsson’s performances in F3 and Formula Atlantic, earned him a test in a Formula 1 car, with Williams at Goodwood, at the end of the 1975 season. He impressed aboard the Williams FW03, and was offered a contract for 1976, but turned it down in favour of an F2 drive with March, which did not require a budget.
Luckily for Nilsson, after just one Grand Prix for Lotus, Ronnie Peterson, tired of the uncompetitive 76, decided he wanted to drive for March in Formula One. As part of the deal, March offered Nilsson to Lotus, where he joined Bob Evans, another new signing in the team, to help develop their new car, the Lotus 77.
The Lotus 77 was promising and the team was undergoing big change and Mario Andretti soon replaced Evans. After a difficult start in South-Africa, Nilsson progressed rapidly. His debut season saw a podium finish at only his third Grand Prix in Spain, and another impressive third place in Austria, a fifth in Germany and sixth in Japan, but the rest of the season was marred by accidents. A steep learning curve.
Picture below: Swede Gunnar Nilsson, here in front of team mate Mario Andretti, on his way to a fine third place finish in his Lotus 77-Cosworth, at the 1976 Spanish Grand Prix at Jarama.

Formula One Championship, Spanish Grand Prix, Rd4, Jarama, Spain, 2 May 1976.