I'm getting ready to replace the thermostat on my Z and just got back from Murray's Parts. They don't have the stock 180 Delco thermostat, all they have are 170-175 Prestone and 190-195 Prestone thermostats. I picked up the 170-175 Prestone, but started to think whether or not I have to have my PCM programmed for this lower temp thermo.

Any ideas??? The price difference was nearly $11 less for the Prestone over the Delco, too.

Any quick responses would be appreciated!!!

 

You don't HAVE to program the car for the lower degree thermostat, but it will help it to stay cooler if you do.

HOWEVER, I'd be willing to bet that what you got isn't a thermostat for the reverse cooled LT1. Sounds like it's a traditional SBC thermostat which will not work correctly.

 

It should look like this.