Alright, update on the situation. I gave it a pretty thorough Seafoam treatment and that seemed to help a little. It wasn't missing driving it in second gear down my little road like it did earlier. I decided to take it for a drive around and it did about as well as it did when I drove it a few years back. I drove it for about 10-15 mins twice today.
Engine braking makes some little "pffts":
https://youtu.be/dwF_Dt1UWac
Climbing up hills is slow going and gets smokey. I know I have a few significant exhaust leaks around the manifold and the manifold to muffler clamp area.
https://youtu.be/vwEFWsOERJA
I mainly wanted to get the truck going well enough to give my mom a ride for her birthday. I have another engine that I'll look to put in over the winter when I have more time. This one is clearly on its last legs.
Thanks for the help everyone. It was fun to drive it again.