hey guys. i am still working on my 84 eldo and i am in the middle of rebuilding the cylinder heads. i took out all the valves, springs, retainers and keepers and inspected them. the valves had a crazy amount of carbon on them so, i hit them with a wire wheel, degreased all the rest of the valve components. the heads themselves look pretty good except for the coolant passages. they are not blocked or nothing but, i removed all the rust and or scale chunks i could with a long screwdriver and look better but, still not ready to put them back on. i dont have a lot of money now to take them to a machine shop so, i was hoping for a cheap alternative. i know this may sound crazy but, someone told me to try CLR on them since they are cast iron and not aluminum. not trying to get them perfect but, i just dont need to have some good size chunks breaking loose outa those heads when i go to start the car. have a brand new radiator for it and dont want to have a clog in it. do you think the CLR would work or, is there anything else i can try? it has the 4100 motor.