According to the calculator a VO2max of 53 is equivalent to a vVO2 of 10.14mph or a 5:55 pace. This means a desired goal of a 3:23 marathon pace (7:44) is 76.5% of your VO2max. Most marathon runners are somewhere between 60%-70% (for you 9:51 min/mile to 8:27 min/mile) but elite runners can take the percentage as high as 85% (for you 80% is 7:24min/mile and 85% is 6:58min/mile). So a 3:23 pace is aggressive for your current VO2max value. However, the faster you get the closer you get to the elite levels of %VO2max necessary to reach certain goals.
Over the entirety of the marathon you will burn an estimated 4027.7 kcals. Given your pace is 76.5% VO2max, it is estimated that 2878.2 kcals of the 4027.7 total calories burned will come from glucose. Assuming an average male leg muscle mass of 20.0kg (21% of your body weight), you have 1603.6 calories of glucose stored in your leg muscles. This means without tapping into any other source you will have a deficit of 1274.6 calories of glucose. The average person can take an additional 100 kcals of glucose from the liver without putting the body in danger, thus your final deficit total is 1174.6 calories.
This means that either through a carb loading schedule prior to the race, or a nutrition plan during the race you need to consume an extra 1174.6 calories to complete the marathon without hitting the wall at the pace you desire (3:23 marathon) given your current fitness level. This breaks down to 347.5 calories per hour (or 86.9g of carbs per hour (293.6 g carbs in total)) if you decided to only use a nutrition plan during the race. To properly absorb 86.9 g of carbs per hour you would need to consume 43.5 ounces of water per hour (in ideal environmental conditions). This is very close to the human carb absorption limit of 90 g per hour. This means it is almost an absolute must that you have to carb load, and carb load well to meet your goal time without bonking. I don't have a conversion of total carbs consumed to storage ability but I have to imagine it isn't 100% which means over the 3 day carb loading period you need to consume at least an excess of 293.6 carbs.
You would also be a good candidate for attempting to increase your bodies storage capacity. This is done with 1) not taking any nutrition on any run less than 90 minutes, 2) any run longer than 90 min try to find your limit for on the run carb consumption (or water consumption limit), 3) Eat 1/2 your body weight in pounds in grams of carbs (for you 105g carbs) within 15 minutes of coming home from any run longer than 120 minutes 4) Lastly, look into depletion training (Training with no nutrition before running or during running on runs lasting around 120 minutes). Be careful with depletion training, as it should be done no more than once every three weeks, and shouldn't be done within 8-10 weeks of race day. Also, take emergency nutrition with you as these types of runs can be risky under bad conditions.
Best of Luck and let me know if you have any questions.