Water temperature
 

What are typical water temperatures for a 496 HO at cruise and WOT?

My 2002 496 HO closed cooling runs in mid 160's even after WOT run. That's from the ECU vessel view.

I had a 2004 model that ran 170ish. Didn't really matter WOT, cruise, etc. There is a 165* stat in there.

160s

Water Temp
 

That’s about mine, but perhaps a little higher at WOT. I might need to back flush my heat exchanger of that can be done. I also plan to add VesselView to get more and accurate data.

162 at idle, 158 at cruise, 168-170 after running coming off plane until it returns to idle temp.

Not a direct comparison, but I have a CPPerformance FWC system on my 800HP 565’s and mine run 150 all day, every day. It’s uncanny.....

Thermostat
 

Would it be best to change the thermostat if I have no idea what temp it is, or where it is actually opening? What thermostat is recommended for this motor?

I think stock is about 165 thermostat. Mine ran a high of 180 in the Havasu heat but typically would be 170-175.

FYI the Whipple supercharger kit replaces it with a 120 degree stat. It now runs about 140-150 with the same stock heat exchanger.