I used Heim joints (or as under-medicated Arizonians say, "swivel eye balls") on my '49. I know it is a different animal than your '56, but its close enough to apply.
I found that matching the length of the shifter box arm with the length of the transmission lever, gives you a good feel on the shifts, while not exceeding the limited range of movement of the gear shifter on the column.
I used 5/16" Heim joints and a 5/16" steel rod from Lowes which I threaded to fit the Heim joints. I had to make 2 bends in the vice to clear the brake pedal lever and the toe board.
I set up the length of the rod so that the "Drive" position of the column shifter would be at the 3 o'clock position.
Carl
Last edited by 52Carl; 08/30/2016 3:42 AM.