There are probably a few different places that the "General" put negative battery cables on small blocks. I use the threaded hole on the fuel pump boss - the lower one. It's less conspicuous than the water pump bolt IMO. Don't forget the upper threaded hole on the fuel pump boss must be plugged or oil will leak.
The ground straps are placed at different places to make sure there is good electrical contact across parts of the body and chassis that are isolated with rubber mounts (body mounts and engines mounts mainly). My 68 has braided copper straps from the valve cover to firewall, firewall to frame (by the passenger body mount), and neg batt terminal to the pass fender.
You would think that the ground strap from the valve cover to the firewall is redundant since the negative cable goes to the front of the block, but I think you need a good ground close to the ignition to reduce electrical noise.