Under what conditions do you experience the above overheating - at idle, during local part throttle driving, at freeway speeds under part or heavy throttle?
What is the coolant mixture?
When you open the radiator cap after a high temp event, is the coolant full, to the top of the fill neck?
Do you have the correct LT1-specific thermostat? What temperature?
Is the engine modified in any way? Stock program or reprogrammed PCM?
Manual or auto trans?
Is A/C functional?
Have you verified fan operation. A 94 can have two different fan strategies - early production: 2 relays, fan #1 on at 226°F, fan #2 on at 235°F. Or - late production: 3 relays, both fans on low speed at 226°F, both fans on high speed at 235°F.
Have you scanned the PCM for codes? There are codes for the coolant temp sensor in the water pump housing, and for the fan relay signal circuits.
Any signs of a blown head gasket?
What is the coolant mixture?
When you open the radiator cap after a high temp event, is the coolant full, to the top of the fill neck?
Do you have the correct LT1-specific thermostat? What temperature?
Is the engine modified in any way? Stock program or reprogrammed PCM?
Manual or auto trans?
Is A/C functional?
Have you verified fan operation. A 94 can have two different fan strategies - early production: 2 relays, fan #1 on at 226°F, fan #2 on at 235°F. Or - late production: 3 relays, both fans on low speed at 226°F, both fans on high speed at 235°F.
Have you scanned the PCM for codes? There are codes for the coolant temp sensor in the water pump housing, and for the fan relay signal circuits.
Any signs of a blown head gasket?