Grounds. Ground the body to the frame using an 8 ga or heavier ground strap. Might think of using two of these; one at the firewall and the other back near the gas tank to make the sending unit for it as well as the tail lights happy. Ground the engine to the frame; same size of wire. The factory or default ground for the Battery is a heavy black lead that usually runs from the battery to the engine; sometimes to the upper alternator mounting bracket, otherwise using a bolt and securing it to one of the open threaded bosses on the heads. Thinking here that all the ground wires ought to be the same gauge as what the factory used for its battery ground at a minimum.
The rad cradle, which, by the by, is rubber mounted using the same style rubber doughnuts as the body does, gets its ground the long way; that is by way of the bolts that attach it to the fender, and then through the bolts which attach the fender to the firewall/body, and finally from the firewall through the body to the frame and back to the battery.
There should be be a couple of ground straps made of woven wire that attach to the back of the engine, either to the block or to a bellhousing bolt and to the firewall; could be one or two. They are most probably present to make the gauges and switches in the dash a bunch of happy campers.
So? Try running a ground lead from the rad cradle directly to the frame. Why? Because the Headlight ground terminals don't run to the frame, they get attached to the rad cradle. Grounding the cradle shortens the ground circuit and eliminates a lot of potential for breaks or "groundus interruptus". Doesn't have to be battery grade, say 10 gauge primary.
Also, if you can lay hands on one, try testing the headlight sockets to see if they are getting power.
Nick
The rad cradle, which, by the by, is rubber mounted using the same style rubber doughnuts as the body does, gets its ground the long way; that is by way of the bolts that attach it to the fender, and then through the bolts which attach the fender to the firewall/body, and finally from the firewall through the body to the frame and back to the battery.
There should be be a couple of ground straps made of woven wire that attach to the back of the engine, either to the block or to a bellhousing bolt and to the firewall; could be one or two. They are most probably present to make the gauges and switches in the dash a bunch of happy campers.
So? Try running a ground lead from the rad cradle directly to the frame. Why? Because the Headlight ground terminals don't run to the frame, they get attached to the rad cradle. Grounding the cradle shortens the ground circuit and eliminates a lot of potential for breaks or "groundus interruptus". Doesn't have to be battery grade, say 10 gauge primary.
Also, if you can lay hands on one, try testing the headlight sockets to see if they are getting power.
Nick