Oh man what a journey. Almost too much for an old man like me (late-40s). But with help from various folks (including LOWTECH from Datsun1200.com) it was an ultimately successful trip.
I visited old friends and several relatives too, which helped me keep positive.
The old A12 was perfect for the first 900 miles. 170 mile to Oregon, down the length 300 miles to California border. Then I saw Mt. Shasta.

It even went 5000 RPM for much of the trip through the Great Valley of California, at outside temps up to 104 degrees. I kept getting overheated and occasionally poured water on my head. In fact it took me a long time to go the length of California because I stopped every hour to cool down myself. The A12 had no problem all during this time.

It made it up and over the Grapevine (mountain pass into LA) during mid-day with no problems -- I even passed everybody doing the speed limit of 65 mph (106 kph). 

Passed this Datsun Roadster at the top of pass, which was headed for JCCS

After I went over the pass at mid-day on Friday, I had a long lunch then checked the radiator. Not a drop of water was missing. 

So it was a huge surprise that just a 1/2 hour later it massively overheated. I was doing about 4500 RPM and the outside temp was 100 degrees, very hot, but passed a truck up to about 4800 RPM. That was when it happened. It was about 3 pm, and I ran slowly to the offramp about 1/2 mile away-- which is undoubtedly what cooked the A12. I should have pulled over immediately on the side of the freeway. It happened on the Pasadena freeway. I coasted up the Rose Bowl exit offramp.


While I was there, three Datsun pickups went by, like this 620:

On the side of the road, I pulled the plugs and tried to do a compression test. But water came out of all four spark plug holes. Crikey!
I called LOWTECH and he said I change the headgasket at his house, so I had it towed there which was about 20 miles away.



To be continued...