I just replaced the water pump new and took out the thermostat because it was stuck closed and didn't have the 40 bucks for a new one yet. When I had the van engine running and normal temp between 185 and 210 I took off the radiator cap not thinking and I had a fountain of coolant coming out of the radiator. Could this be a sign of a blown head gasket? It also has the 6.0 v8
The coolant system of a typical internal combustion engine is designed to operate at greater than atmospheric pressure. In so doing, the temperature of the coolant can be raised above "normal" boiling point.
As you've noted, your engine reached normal temperatures, which would also imply that it has reached normal pressure as well.
When you removed the cap, the previously-pressurized coolant system was subjected to a rapid reduction of pressure. This very likely resulted in much of the coolant going from a liquid state to a vapor state, also known as boiling.
Your fountain of coolant is the result of the removal of the cap. There is no indication of a head gasket problem. If you begin to see milky foam in your engine oil, or oil in your coolant (check when cold) you may have that concern.