I thought I would do an easy job today and flush the coolant from my 50 with the 2.0L. I've got one of those flush kits that come with the "T" adapter, but I can not figure out where to install the T. It is supposed to go into the coolant inlet hose. on my truck I see two hoses going into the firewall where the heater is. It seems like one of these should be the inlet hose but these hoses are a larger diameter than any of the "T" adapters that came with the kit. The hoses come and go in all different directions one splits off and goes into the carb and the other wraps around the side of the engine and eventually ends up at the water pump. This hose seems like the one to cut into but it's metal.

How do you all usually go about flushing your coolant?