Radiator issues (maybe?)

[Spline64]

I am truly sorry if this is the wrong forum for this, Google searches aren't helping me much.

Thermostat went bad, became stuck closed, drove to work (no temp gauge so no clue and heater was not happening at all and it normally works) and when I got there steam and lost over half my coolant. crap....

Removed thermostat so I could go to auto parts store and get a new one. Replaced coolant. Ran cold to warm as expected till I got home.

Put in new thermostat, 15 deg higher rating as that was the recommended for my engine (180 old now 195). Now heater is working great, but noticed that top manifold intake hose is still cold. Could this be the fact that it just hasn't heated up enough yet? Haven't taken it for a drive yet, and noticed that where the heater core attaches and cap side of the radiator is hot while the top hose (manifold intake) is still cold.

does it just need to get hot before it opens?

thanks,
Spline64