I like where your head is at. It's possible, but it's gonna hurt! Cardio-wise you can finish a marathon at a slow pace with that plan, but weight training for the legs is not a substitude for training for the 4+ hours of pounding - on concrete! Of course every body reacts differently, but the pounding is the issue for most people and it can really take a toll on the under trained. And cause injury. Keep in mind that your long run of 16 is a full 11 miles short of your goal - so you're gonna be forced to make up a big gap on race day. Again, I'm not saying you can't do it, it's just not usually advised w/so few miles of training. Best of luck, Paul.