Just for those that are confused about the Ford spark plug issue. There were 2 problems. On the older motors there were not enough threads to hold the plugs and there was a problem with the engine spitting the plug out and stripping the plug hole which then required the head to be replaced or helicoils to be installed. The 2nd problem was that Ford used a 2 piece spark plug and the hex drive was on the upper half and if the plug got tight from age or mileage or lack of antisieze the top of the plug would break off with nut. Ford made a special tool to remove the plug but you had to go to Ford because they would not sell it to independent garages. There is an aftermarket 1 piece plug that does not have this problem and any mechanic worth 2 cents would not put the factory original plug back in after getting the old ones out. I do not know if or when Ford stopped using the problem plugs but you could just pull a boot and check the plug number to see if its the aftermarket or original.
