My 96 Z28 will pull up to about 250 with the AC on, driving on the highway, with 98 degree weather. Even with a 160 TStat and custom tuning, the car runs this hot. On a cooler morning, approx 75-80 degrees, the car will still pull up to about 220-235. The car has a new water pump, radiator, hoses, and a fresh LT4 kit. I have tried bleeding the system several times resulting in one little "burp". What else can I try?

 

Are your fans working properly?

 

Fans are working properly. On first and second stage 192-off-182. Hysteresis 5 degrees.

 

Air pocket somewhere in the system.

Did you fill the water pump with water before putting the tstat on when you installed the pump? If not, thats usually a cause of air pockets.

Use the bleeder screws and make sure your overflow container has water in it.