I have the same problem. I replaced the SM420 with an A833, in my 63 C20. As Mark has pointed out an emergency brake is a requirement. You should be able to use a emergency brake that attaches under the steering column. That is what my first 63 C20 had. The setup is basically the same from 63-72(?). I replaced the rear axle in my 68 with a 73 and didn't have a problem with emergency brake cables. Find a donor and get everything from the backing plates to the handle under the column. You may also need the tranny cross member whether the tranny needs it or not.

Larry

Last edited by LGriffin; 09/28/2009 9:52 PM.
I don't own a vehicle that isn't old enough to drink.