These are the basic parts of Ford truck body mounts (cab, NOT bed). Note that the necked portion of the upper sleeve (alone at the bottom of the photo) is designed to lock onto the lower sleeve (on the R end of the bolt) to hold the rubber in place on the frame on the assembly line. But it funnels dirt & water in around the 2 parts & the bolt threads, usually rust-welding them together. So the longer they're soaked with penetrating oil before disassembly, the more likely they are to come apart.
Once the bolt is backed out a few turns, spray more penetrant down into the upper sleeve to rinse the rust off the threads, and use a hammer & drift on the bolt head to separate the sleeves. An air hammer can save some fingernails. They sometimes have to be cut apart and replaced. Always make the cut as HIGH as possible above the frame (close to the body).
The core support mount is different, and the bolt threads into it from below. It's virtually impossible to unscrew the bolt intact because of battery acid &/or road salt eating the bolt away, as shown later in this album.
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