Originally Posted by VALET10
I Am Using Mattsons Radiator Module With Twin Electric Fans Built For My 55 Chevy. I Think Rad Cap Is 16 Pounds Pressure.THE GAUGE READS 185 DEGREES AT IDLE AND IT TOOK NO LONGER THAN 5 MINUTES TO GET THERE.
So is it puking up at 185, 5 minutes is well within reason. Is it actually boiling over due to temperature or is it just puking up coolant. If it is running at 185 with a 16 LB cap, I doubt it is boiling. The boiling point would be roughly 265 or more depending on your coolant mix.
Start it and put a thermometer in the radiator and see what the temp gets up to, if it starts to puke coolant, check the temp at that point.
You could have a bad head gasket or something else adding presure the to cooling system.