This is 86 Volvo Turbo - Inside car heat level seems like it could be higher and it seems to heat-up slower inside the car compared to the temperature gauge.

I've already flushed the coolant two weeks ago. Ran the garden hose backwards through the heater core, seemed unblocked and no sediment.

Heater valve is the metal motorcraft YG model installed a year ago and I checked it for flow when I did coolant flush. Thermostat is about 12 months old (Wahler 92C).

Now before I get a chorus of "change your thermostat", is there anything else to consider for this problem?
I'm trying to work through the logic of the problem. If all the main parts, thermostat and heater valve are working, *how* could the heat in the car be inadequate? (blower works great too).

Maybe I just never got over how great the heat in my 240 was?! Still the 740 should match the 240 in heat.

Thanks DaN