Do I need to dimple frame for power steering on 67 GMC?

[hpcgmc]

I've read that some of the later year 1967s don't require dimpling the frame to install power steering. I haven't seen a dimpled vs nondimpled frame, so don't know what I'm looking for, or what it takes to dimple my frame.

Here's a couple pics of the stock steering box and frame in my 67 GMC. Can someone tell me if I need to dimple the frame, and if so, maybe show me a pic of a dimpled frame?

Thanks!