Radiator/Engine temp questions
In 1976, I rebuilt my 340 for fuel economy due to the crude embargos and middle east tensions (sound familiar?). I used a 318 cam and stock compression (10.25:1), an SP2P manifold and really tuned the AVS for best fuel economy. I went to a 4 core OEM radiator and electric fan to replace the direct drive fan (no fan clutch).
I drove from Irvine where I was a grad student to Tucson in June for a chemical conference and took my brother with me (10 years younger). It was 117°F in Tucson and the combination ran at 180-185 cruising and the fan came on at 195°F climbing hills. This was really nice except for it being a black Formula S FB with no AC. Drank lots of lemonade during the drive. But the combo got 22-24 mpg with 2.94 gears. Cannot complain about that.
I had to be up early for the conference, but my brother took it racing every night and never lost. Must have been week competition in Tucson.
Still have that '68 as you can see in my photo.