Hello tonyf787,
Can you be a little more specific about which adjustable rod you need dimensions for? Are you looking for the length of the longitudinal service brake rod to the rear axle, or the ones actually attached to the rear service band? For '29 there are two adjustable eye rods at the service brake. It is quite a unique style, much different from the '28.
Is this a project car you bought in pieces, or partially disassembled? If so we can help you determine if all your pieces are '29, or if someone inadvertently threw in some '28 parts as well. It happens all the time. They are very similar but just different enough it will screw up your adjustments.
Art