This would be for the non-competition suspension Cougars. U-Bolt length 7 inches, and threads 1-1/4 inch in length.
U-Bolts include two (2) correct style attaching nuts 7/16-20 threads. This size of U-bolt seems to be the most common found on Cougars, no matter the leaf pack stack.
Ford part number C7WY-5705-A.
Standard suspension U-Bolts run about 6-3/4 inches in length, see related items.