Review on ❄️ Zerostart 310-0005 Engine Block Heater: Superior Cold Weather Performance by Fred Novak

Used on 2004 Chevy 2500HD Silverado LT with 8.1L engine. First, make sure you have the right tools - a 1/2" 17mm hex driver to remove the brass plug from the cylinder block. The brass plug is then located on the driver's side near the front of the engine. Use a long 1 /2.2 (more than 15") to get to the plug. It's very easy to get to once you find it. Drain all the coolant from the overflow and radiator. Removing the plug will drain a lot more coolant .Wrench 26mm (or 1 1/16"). Remove the front skid plate and you have easy access from the front. You cannot use a 26mm head due to clearance issues in the frame.