The max load on all the parts in question would be at wheel lock up. While power disk brakes might be easier or occur with less effort on the driver’s input. Lock up is the same forces no matter the brake used. A good drum brake should be able to lock the wheels at will........with some serious driver effort.
I would agree that the whole suspension and steering system should be looked at during any restoration or upgrade. Sloppy king pins, loose steering box or worn out spring shackles can make any emergency stop a real adventure.
