No. Health is far more important.
> Are the long hours required to deliver a good piece of software?
Be suspicious of anyone who tells you they are/are not required. You have to put in a certain amount of time in order to really understand what's needed. Whether you put that in over the course of the project, or all at the end is up to you.
When implementing, I put pressure on myself to find insights that greatly simplify the code. It can be as simple as a unified way to organize code, or a messaging subsystem. This isn't terribly surprising, but it requires thinking very clearly about the problem and reflecting on it often. You're not going to be in this state of mind if you're developing in a purely reactive, omg-deadline-in-one-hour style. You may not arrive at these insights quickly, however. So you need to be willing to invest time at the offset, working on the hard parts, and be open to tweaking the program's structure until it feels solid to work with.