Hi Phil,
just had a look and mine has 13psi on the rad, and a non pressurised cap on the expansion tank. I think it was the other way around when I got the car. Looking at the cap it could be original from 1975. Cooling has never been the car's strong point - it now has original header tanks but recored rad, but I put in a flexblade fan on the water pump plus 2 electric pushers thermo controlled and its passable, but that meant I had to take out the A/C rad to fit the fans. Not a car to drive in traffic in an Aussie summer.
regards
Peter