So I tore into the truck. I had previously found out which head was bad. Just wanted to share the photo of it once I took the heads off. You can see the far right one is clean, and I think I just had a small leak in the head gasket which eventually became much larger once I was in Minnesota. So now I am debating if I should take off the oil pan and remove the piston to inspect it and check the ring. Make sure no more damage is done to it that I cannot see.
As for the heads, I am taking them to be machine, possibly do a valve job on them, and have them magnafluxed to check for small cracks.