Yes, fan clutch (see rockauto.com), and at almost 3 decades old I'd chuck the old one and get a good HD thermal one.

 

OE LT1 thermostat is rated @ 180F. That's when it STARTS to open. It's fully open @ 194F.

Unplug the H2Opump temp sensor. The 240W secondary radiator cooling will spin up after a few seconds (patience).
If not within 10secs, time for diagnostics.

Note: GM programmed the 2ndary fan (normally) to turn on when the H2Opump temp sensor hits 232F.
Normally, if the electrical 2ndary fan comes on, either the powertrain is working VERY hard,
or something is wrong.
The mech primary fan starts doing its job much sooner than GM sets the electrical primary to turn on: 225F.

In other words, LT1 cars with mech primary fans tend to run cooler than those with two electrical fans, except maybe in the summer during constant AC demands.
(Those with two electrical fans (V03) and a pcm tune are using both fans to regulate coolant temps somewhat similarly to how the (V08) mechanical fan typically manages to do so by itself.)

Once coolant temp hits 222F, I'd be concerned, although I'd feel better if that's the peak.
Over 230F, look for a safe place to pull over first chance you get to try to find out why.

 

In my experience, LT1s can run a little hotter than stat ratings because of stat placement on the coolant inlet side. Rather than the output side like most small blocks. Also know that over time, thermostats get "lazy". Opening later, slower, and not as far.

 

All are great answers, thanks for the info. I will do the check on the electric fan as suggested. I hope it still works, as I don't think the car coolant has ever read 232, maybe most is 210.

Just realized I do run the airco, (yes it occasionally will get to 100 in the Northwest). Should that activate the auxiliary electric fan independent of water temp?

Best,
Cruiser Bill

 

Just realized I do run the AC (yes it occasionally will get to 100 in the Northwest).
Should that activate the auxiliary electric fan independent of water temp?

The AC psi thresholds are written (by GM) such that - provided the rest of the cooling system is in healthy working order! - the AC thresholds actually keep the engine cooler ... for those of us with V03.

You however, have V08. Your mech fan has its own inherent 'programming'.
It does not care whether or not the AC is on, it simply reacts to underhood engine heat.

Stuck idling in a dense traffic jam on a brutally hot summer day, I can see the mech fan being limited by engine RpM, which might eventually convince the electrical secondary fan to come in and help as needed, RARELY.

Once traffic gets moving and the mech fan gets a lil bit of help from a headwind and increased engine RpM, the electrical secondary will likely soon shut off.

 

For your reference
Quoting Scott Mueller (yes, this is almost as old as IronBlock LT1 engines are):
"B- & D- car coolant fans operate under PCM control at the following engine temperatures and AC system pressures:
Fan …….….…… Mode ….….… Temps ….….… AC Pressure
Primary (RH) .... ON ... ... 107°C / 225°F ... ... 225 psi
2ndary (LH) ...... ON ... ... 111°C / 232°F ... ... 248 psi

Primary (RH) ... OFF ... ... 103°C / 218°F ... ... 180 psi
2ndary (LH) ..... OFF ... ... 107°C / 225°F ... ... 203 psi

Additionally, the PCM will turn off the fans at higher vehicle speeds (above 48 MpH) since running fans can actually impede airflow through the radiator at high speed.
Each fan also has a minimum running time. Once activated, the primary fan will run for a minimum of 50 seconds, and the secondary fan for a minimum of 26 seconds.
Finally, certain Diagnostic Trouble Codes (DTCs) may cause the PCM to turn on one or both fans."
(The above quote has been edited for accuracy.)