The good news, as you just read, is that the new Milwaukee-Eight 131 is a drop-in, street-ready replacement featuring robust Screamin’ Eagle components. The 131 engine brings the same 4.5-inch stroke of the Milwaukee-Eight 114 powerplant but pairs it with new 4.31-inch bore cylinders that have a patented design. Milwaukee-Eight Extreme Ported four-valve cylinder heads are CNC-ported and fitted with 1mm-larger-diameter valves to optimize air-fuel flow and feature machined combustion chambers shaped to optimize combustion efficiency. The engine also gets a high-lift SE8-517 camshaft and high-performance cam bearing, high-compression (10.7:1) forged pistons, a 64mm throttle body and intake manifold, and high-flow (5.5 grams per second) fuel injectors. It’s a recipe that, according to Harley, “produces 131 pound-feet of torque and 121 horsepower at the rear wheel;” or at least does so when paired with a set of Screamin’ Eagle Street Cannon mufflers.