I haven't looked too awfully hard, but I haven't found a bolt-on piston stop that would reach from one head bolt hole to the other on a Ford.
I'm making these out of aluminum, they will be black hard anodized, and will come with all necessary hardware, including a center set screw with jam nut and (2) 1/2-13 bolts and washers for clamping.
These will work with FE's, SBF's, and 385 series engines.
Price would be $29 each plus shipping.