Here's some text from the Hypertech website for programming for the LT1 engine. Depending on where you live, you can drive around with your stock thermistat and see what your car is roughly heating up to.

I live in CA where stop and go traffic is daily event, so I easily get up into the 200s.



• You can select between optimizing the cooling fan temperature settings for:

LT1/LT4 Stock Cooling Fan Temperatures:
Fans on/off at: 240°F/225F°

- OPTIMIZED FOR 180°F HYPERTECH POWERSTAT
LT1/LT4 Cooling Fan Temperatures:
Fans on/off at: 213°F/205F°

- OPTIMIZED FOR 160°F HYPERTECH POWERSTAT
LT1/LT4 Cooling Fan Temperatures:
Fans on/off at: 192°F/185F°