We have a 57 in the shop right now so I measured the bell crank on the frame. It is 11 inches long with the pivot pin 4 3/4 inches from the top. This means that the bottom moves about 1 1/4 times as much as the top. If you bypass the bell crank with a cable run through a pulley or a tube you will have to keep the slack adjusted out of the cable as you will be losing 25% of cable travel without the bell crank. No a real deal killer. If nothing else you can use a pinion mounted parking brake. TSM in Colorado makes them and probably several others.
