I had similar problems. I have a 49-3100 with a 55-235 engine. As you guys know the water pump and fan are lower to the radiator. My radiator was moved foward. I installed a 17 inch 6 blade fan, used spacer as needed to locate close to radiator. Just be careful with spacers. I used a Robertshaw high flow 180 thermostat and the motor runs at 180 with no over heating problems.