Can you verify the hot/cold air door is functioning? Meaning, when you turn the temp control to hot, is the air door responding?

Blend door
It's possible the door is broken, it should give some resistance on the turn knob. If it's very easy/low drag to select hotnorncold, it may have broken the pivot shaft or arm.

Past that, you might have some air in the system.

By pulling the glove box out, you can access all of the door levers. Male sure that the temp blend door is moving all the way when you select "hot" on the knob. If the cable as slipped in its bracket or stretched, it could affect vent temperature.

Secondly, verify that the heater hoses stay hot, even after the vent has gone cold.

Lastly, verify that your cool air bypass door isn't stuck upen. If that happens, it allows cold air to come out of the face vents, regardless of temperature selected. There is a selector to the right of the center face vent (as long as it doesn't have a '99 center vent). Make sure that the knob actually is connected to the door lever and is operating correctly. Again, you can access this door by removing the glove box. It is straight back behind the radio.

Checked the doors and they all shut. The upper hose gets cold after a little while. There isn't a valve in the heater lines right? If not I'm going to try and flush the heater core because I think it's clogged.

Flushed the heater core but it had some back pressure. I'm afraid i need a new one.

Just to verify, is your car reaching op temp?

There is no heater valve. If you take your heater hoses off and pour water in, it should essentially just pour right back out the other side. If not, it does sound like it has a clog. You can try back flushing it with a garden hose (I've done it when I was in a bind) but be careful. The core won't do well with too much pressure. Then you could be dealing with wet carpet, too.