Over heating on the freeway?

A temperature problem at freeway speeds is almost always a radiator problem.

Seems like you’re the second person with a brand new Griffin cross flow that has cooling issues...

4spdragtop said

Ok, I dont know much, but I've read a few threads on cooling as I had an "issue" with our 67 cuda. 200 on highway and 185-190 in town. 273 4 bl, factory 3 row rad, new water pump(8 vane) last year. factory shroud. WAS running 190 stat. Timing cover coolant leak for the 2nd time in 2 years. Put a 160 stat in it and now it has not gone over 175*.
No disrespect to all the theories and such but I got a 35* temp reduction by changing tstat. $12.
Good luck.

Click to expand...

Easy, you changed a broken thermostat for a good one. The thermostat temperature change has no part of it, besides the extra wear and tear you’re putting on your engine running it below ideal temperature.

The thermostat only sets the low temperature. If it effects anything other than the low temp, it’s not operating properly.