[100IH]

I would like to suggest that a Gano coolant filter should be used in the upper hose for some time after completion of the chemical treatment. The rust buildup at the rear of the block is usually more than what anyone would imagine. More rust will come loose once coolant is added and the engine is run out on the road, heading,of course, right into the radiator that has been "cleared" of rust. The filter will catch the rust and can be seen and flushed out until it stays clean. Try a search here for Gano. Flushing after treatment can't get to the rear of the block enough to get it all. That's why it builds up there and causes heat issues.