So I have a 99 Ford F-150 & it is leaking coolant ofc from one of the driver's side heads... I am going to try using this Blue Devil gasket sealer on it & see if it works. It's an old truck & hopefully I can get a year or 2 out of it, that would be great. I went to take the radiator plug out today - It was a plastic bolt, I did not even twist hard & the head of the bolt broke off with the thread still inside the radiator. It has a allen (hex) key hole in the center so I am thinking I can get it out but I would not have anything to plug it back up with. So tomorrow I am going to buy the plug & get back to this project. I will let everyone know how this works out for me.