I bought a 1000W tank style coolant heater that I'd like to try to install on the car (I'll either do this or throw a frost plug block heater on it... $$$$ at the dealership) I already installed an oil pan heater for the oil. The tank style heaters work better anyway.

Is there a block drain on the side/front of the block? There should be. Anyone know what thread this is? I will go to the dealership and have them look up a plug if I need to. Then I should be able to install a plug to barbed connection onto which I can install the 5/8" feed hose for the tank heater.

On the outlet side, I am to splice the outlet of the tank heater into the return for the heater core. Seems there is a 5/8 and a 3/4 hose coming out of the firewall going to hardlines under the intake manifold. It would be convenient if the 5/8 was the return. Looks like this might be true; the guy at the dealership said the lower hose would be the feed, makes sense for air bleeding, as well the larger hose is the one in which a flow restrictor is installed.

Thanks in advance.