'86 Safari Wagon Looses Power on Inclines

The original Thermostat temperature is 195*. Most of the later SMOG era thermostats are. This helps with the emissions on the exhaust side.

190* down the road sounds about right at thermostat. Give or take 5* of error.

What does it run at idle? 230 is a tad hot. You might need to replace the clutch for the fan. Sounds like under a heavy load, the fan needs to pull more air to compensate for the load. But when running down the road the forward movement of air is keeping it cool.

What is going on with the clutch?

Dave

http://www.rockauto.com/catalog/moreinfo.php?pk=1793434