GM Vortec 8100: The Most Reliable Big-Block V8 GM Vortec 8100 Is The Most Reliable With the Big-Block V8 Engine Ever Made (Via Chevrolet) The GM Vortec 8100 is the most reliable big-block V8 engine ever made. It has 340 horsepower and 455 lb-ft of torque. This engine was used in heavy-duty trucks and SUVs, featuring a strong 18-bolt…