Hi all. This motor style is new to me. With the strange heater hose system(1 to radiator and 1 to top of manifold) how do you back flush the cooling system? Does not seem like the block will flush?

 

You can still pull the drain plugs on the side of the block near the oil pan rail to flush.. remember there may be a build up of crap behind the plug that needs a poke from a screwdriver to loosen up. Easy enough...

 

To get any kind of circulation on the cooling system while the motor is cold you will need to remove the thermostat. Per its design it stays closed until it gets to operating temp and no one wants to mess with the system when its hot. You could remove both radiator hoses and flush the radiator and motor seperately or leave one attatched and do it all at once. I would prefer to remove both hoses so nothing gets stuck in the radiator from the motor or motor from radiator. Its very mesy but the best way to do it yourself. The other option is to take it to a shop and have them hook it up to a flush machine that does it while its hot. They basically put the flush machine in the coolant loop and run the car....out with the old and in with the new.