Grumman teamed up with General Motors to build the LLV using a chassis from the 1983 2WD S10 Blazer and the “Iron Duke” 2.5L inline four-cylinder engine. The Iron Duke was known for its bullet proof reliability. Specs were said to be right around 100hp and 125lb-ft of torque so you definitely won’t win any races with it. But the stop and start type of driving that most mail carriers do it was perfect.