Ok, I went back to the house to install a new heating element yesterday. Before I did that, I checked the airflow at the vent to the outside. That's fine. I checked the suction side of the filter and that's fine. Then I checked the suction side at the heating element and noticed that it wasn't pulling very much air. Was ready to start taking apart the machine when I noticed an air gap on the drum seal.
This picture shows the light from my work light from inside the dryer. There is also an air gap on the front drum seal as well. So now I'm ordering a replacement seal and hopefully will resolve this problem.