327 overheating
 

I've got a 327 that's been running great for a couple of months now...

The engine temp usually runs around 185(night), and 210(day) when it's about 90 plus degrees outside. It has a 185 Thermostat.

The outside temp is 83 today, and after going on a quick 5 mile round trip errand the engine temp hit 235.

Any ideas on why it's getting hot all of a sudden?

Re: 327 overheating
 

Too many things can cause overheating. The list is fairly long but start with the easiest and cheapest first (not necessarily in order).

-Radiator cap
-Collapsing lower radiator hose (weak or internal spring rusted out).
-Clogged radiator or defective
-Sticking thermostat (test it in an old pot on the stove)
-Head gasket or crack in the head
-Not enough coolant (install an overflow tank)
-Radiator fan clutch bad (if using one)
-Install a shroud if there isn't one

There may be other causes but this gives you an idea.