I measured a stock '32 wishbone on the axle at 47 1/2" from the center of the top hole of the wishbone yoke at the axle to the center of the ball. Those perches are Model A, they will work with hydraulics and their appearance can be cleaned up quite a bit. The left spindle is a '37-'41, so called "round back", and hydraulics go right on with plenty of disc options too if you are so inclined. BTW, a commercially available steering arm can be used on that spindle with an adjustable drag link, or you can use cross steer with a '37-'41 right side spindle.