[hatzie]

The ground strap should run from one of the drilled and tapped accessory bracket holes in the RH cylinder head to the cab.

Look at the 1976 wiring diagrams. THE FOLLOWING IS 1976 SPECIFIC.
In 1976 main power feeds (Circuit-2) is run through a fusible link on the BAT stud of the starter to the J-studs on the firewall next to the brake booster. Other years may have two or three fusible links 1976 has one.
The Circuit-2 output runs from there to;
the V & BAT terminals of the alternator.
the Bulkhead plug on the firewall into the cab.

Inside the 1976 cab you will find a splice that routes power to several points inside the cab. See the wiring diagrams for where.

If the fusible link at the starter fails on a 1976 truck all power to the interior of the cab is shut off. You can check for power at the J-Studs on the firewall. If there's no power there you have a break between the J-Studs and the Starter BAT stud... Probably the fusible link. On a 1976 V8 the fusible link is 14 gauge attaching to a RED 10 gauge SXL power feed wire per the wiring diagrams.

Circuit-2 power distribution varies a lot over the 1973-1991 model years. The above only applies to 1976. You should consult your model year wiring diagrams.