Mary Barra, General Motors Co.’s chief executive, spent weeks preparing for an onstage unveiling of the electric Chevrolet Silverado , GM’s big play in the fledgling market for battery-powered pickup trucks. Ten miles away at Ford F -0.18%▼ Motor Co.’s headquarters, executives were plotting a pre-emptive public-relations strike, said people familiar with the plan. The day before Ms. Barra’s presentation in January, Ford said it would double factory capacity for its F-150 Lightning electric truck , citing overwhelming demand. Ford shares surged 12% that day. Within days, in private meetings with investors, Ms. Barra was facing questions about why Ford’s truck would beat GM’s to market by a year. “They want to better understand the portfolio of EVs that we have coming,” Ms. Barra said of the meetings, adding that the topic didn’t dominate the conversation. The Ford-GM rivalry —one of the business world’s fiercest for a century—is taking […]