If you're going to school full time, forget it. 1650 is on the low end of billable hours, but it's very much full time. It would probably require 40 hour work weeks at least.
If you're going to school part time, and it's expected you'll have a job, it might work. What I'm wondering is what you would be doing as a 1L with no legal training. I'm not even sure you would be allowed to do legal work, you might need a certain number of credits before you're allowed to work in a law firm even under the supervision of a licensed attorney.
If you are going part time and want to do this (and it checks out OK with the rules), make sure it is very clear what is expected of you. Is 1650 hours a target, or a requirement? Is that the only requirement? If this is a medium-to-large firm, they can have extra requirements (like extracurricular activities) that can run into the 100s of hours. Ask how much you can telecommute or whether you'll be expected to be in an office all day.
It will be time consuming and difficult, and you'll have to make sure you separate your real legal knowledge from law school knowledge (trust me, it's different). But you'll gain some invaluable experience. Just don't do that at the expense of setting yourself up for bad grades and/or possibly getting fired if it seems likely that one day you're going to have to choose between getting school work done and getting firm work done.