62 C10 Rear E-Brake Cable on later 12 bolt rear end

[robber grin]

I have a 1962 C10 with a 73 K10 12 bolt rear end - 11 5/16 x 2 3/4 rear drum brakes.

I'd like to try and keep a factory style e-brake system... 62 front cable should still be usable if I keep the levers/bars at the center point of the frame.

It's been a while and I'm wondering how to get the rear cable length right for the later style backing plates and still tie in at the center point levers -

I figure it's that or scrap the bars and go to a 66 C10 style set-up with all new cables.

Would someone school me on a solution?

Thank you,
Bob