Given your location, Cleveland Clinic is where I'd start.
I live in southern missouri
I had surgery in early '04 for a 5.0 cm ascending aortic aneurysm, I was 45 at the time. At 4.8 cm, you are just under the surgical threshold. I suspect that your chest pain may be unrelated, as most people have no symptoms at this stage of an aortic aneurysm. While you may be misinterpreting your surgeon's concern, you should consider getting a second opinion. I strongly suggest that you find a surgeon with a great deal of experience with aortic aneurysms - I'm talking about someone who has performed hundreds of these surgeries, not someone who has done a just a few. Cleveland Clinic has such surgeons. Where are you generally located?
You may want to try and post your question on the "Ask a Doctor" forum. Click on the link (above, left) and try and ask the doctor. He/she may be able to give you some advice and/or information.