Head Gasket???

[High Risk]

I have a '91 Burban. It keeps creating pressure in the radiator and when a low idle or when shut off it blows anti freeze into the over flow. Last radiator had so much pressure in it it started ripping apart. Now have new aluminum radiator and still creates lots of pressure. Engine runs great except it blue smokes when started and every now and then after. Also misses slightly at high RPM's. Doesn't seem to be anti freeze in the oil. Any ideas would be appreciated. Love my 6.2!!!
Should I change the spark plugs? (J/k) :-)
High Risk

[93GMCSierra]

Possibly exhaust gas going into the cooling passages, blown head gasket or cracked head is the most likely scenario, is there any discoloration in the coolant?

[High Risk]

No. Doesn't seem to be any dicoloration at all. Very green. :-)