If you're an AMG with decent test scores and a dean's letter that doesn't contain any major red flags, residency application is as much about you finding the program that will give you the training you need as it is about convincing them to take you. Many academic programs in IM have de-emphasized clinic medicine to the point where it is actually hard to graduate feeling confident in your ability to be a good PCP.
When you go to interviews, you need to be asking questions about the program's ability to provide you with a good clinic experience - true patient continuity, seeing enough patients to feel comfortable with work flow and volume in clinic, and seeing a variety of complaints, from chronic disease management to minor acute problems. It is probably safe to say that more than half the clinic opportunities offered by the top 50 academic IM programs will fail you on one or all of these fronts; you won't see enough patients, you won't see your own patients (and get to know them), or you won't see acute care issues because you do have your own patients and since you're only there 1 day/week, they wait a long time to get in to see you, so there are no last-minute bookings. Most of the top 50 programs have a clinic or two that will adequately prepare you for primary care (or a track) but you need to be open about what you want to do in order to figure that out.
I would also argue that going to a top program might lead to a miserable 3 years of you getting set aside and sent to the back of the line for scheduling, research opportunities, etc because you don't "need" certain things if you "just" want to be a PCP. So you need to find a program that will value what you want to do, and will help you get the training you need to do it the same way they help someone who is applying to cards or GI. (The PCP internist is a dying breed, but a very valuable addition to the community of medicine, and one that some of us suspect will be missed a few years from now when we figure out that having multiple sub-specialty clinical 'homes' isn't the most cost efficient _or_ the most effective way to practice medicine.) I didn't train at any of the top 20 institutions, but I suspect that as GlutonNC suggests, they might not prioritize your needs, because they might have the mistaken impression that primary care is for suckers, or that training in their hallowed halls will surely graduate you ready to be a great primary care internist without even thinking about what skills you might need to hone. (It's an easy job after all, in their minds.)
Do you want to spend 3 years of residency training somewhere where your colleagues are all trying to throw you under the bus lest you get in the way of their fellowship dreams, and where what you want to do is perceived as less valuable or easier than what they want to do? Or do you want to go somewhere that will recognize the value of what you want to do and prioritize you equally? If the latter is true, you should interview broadly in the geographical regions you'd be happy to end up with and ask specific questions about primary care training. It'll be easy to tell if it's something they care about.
