How does Endurance and leveling up effect HP?
Solution 1:
A great deal of research has been done on it. This thread has a lot of good information.
The short answer is, when your dweller levels up, the amount of HP they gain is based solely on Endurance at the time they do so. So being E10 w/ +7E gear will give the most HPs.
Once I get dwellers to E10 I equip my best Endurence gear (sadly not +7) and send them out until they are in danger of dying or find 'better' gear that isn't Endurance based.