Couple of days ago the temp gauge went to 220 and she started to spit out antifreeze out the overflow. I changed the thermostat today, all they had was a 195 fail safe thermo. Now she runs 205,210 I bought the car in mar of this year and she ran 180,190 200 tops. It has the big aluminum radiator, flex fan and stock type waterpump. Do 429 run hot or am I missing something?