Clogged Heater core

1994 Dakota and the flushing was done in April of last year. It seemed much warmer after the flushing, but now that the weather is in the 20s it surely is more noticable.

I’ve never cut a core apart but I presume the fluid is flowing into the top of the core’s tank and right back out the outlet tube instead of flowing through the core tubes or only flowing through very few of the tubes… Is that possible???

The temp in the Radiator (new this summer) is at 174 degrees. With a new thermostat.
I think that was a 185 degree thermostat and the 174 would be normal with it just sitting and the fan helping cool the fluid.

I checked the blend door also and seems to be working properly.

when flushing I connected the drill pump hoses to the core inlet and outlat and the reversed the flow too.

THe inlet hose to the core is nice cand hot, but the outlet hose is no where warm enough.