The Olds sourced 213/230 L-head engine used in 36-37 had bearing inserts and was a full oil pressure engine. These engines had different cams, distributors and carbs than the car engines. The Pontiac 221 engine was used in 1938 and I have no idea why GMC used that engine, maybe supply issues with the Olds engine?
GM still tries to market the GMC as upscale to the Chevrolet truck. Putting a bearing insert full pressure was GM's way of saying yes they share sheet metal and other parts but the heart of the GMC is what makes the GMC better. It is what we call marketing today salesmanship back then is my guess. Jeffrey
