The engine stabilizer rods were installed on 1948 and older Fords because of the transverse rear spring and the torque tube.
On a conventional rearend with parallel rear springs and a modern slip yoke driveshaft, the motion of the rear wheels is transferred to the body through the parallel leaf springs, the rear springs are actually pushing the body down the road.
On a vehicle with a transverse spring and torque tube, the torque tube and spring are pushing the vehicle down the road. This means that during acceleration the torque tube is trying to push the engine through the radiator.
Model A’s had solid motor mounts so the engine could not move, When Ford installed rubber engine mounts in 1932 they had to install stabilizer rods to keep the engine from moving. Apparently, the 1932 chatter rods were too weak because I find a lot of the ‘32 chatter rods that have been broken and re-welded. The later chatter rods were a larger diameter and appear to be a lot stronger.
In 1949, Ford dropped the torque tube rearend and went to a modern slip yoke driveshaft with parallel springs. The chatter rods were no longer needed so the 1949 -1953 8BA blocks do not have the holes in them for the rods. If your building a hot rod with a torque tube rearend you should use a 1948 or older block with the chatter rod holes in them. There were aftermarket brackets available for installing the later 8BA blocks in earlier chassis. These brackets locked the motor mounts to the front cross member (see attachment).
Jerry