Tight!
They are so close to center that I guess Ford found out that they don't unscrew and did not need the wire. They are installed without lock washers, don't use then. I just pull them tight with a standard 1/2 drive ratchet.
Torque values in the Model T and A era were set by the length of the proper wrench for the job.
Rod nuts (3/8) are about 35, head bolts (7/16) 40 to 50 (35 to 40 on the early blocks) so should be some where in between 40ish maybe.