Preparing For Sri Chinmoy Williamstown Marathon 30th May

Mixed results in my preparations thus far. Either pulled or tore the upper part of my left calf about 13 days ago after 3 days of high mileage, requiring a day's rest, and slow and gradual increase in daily mileage, and when I think all was well, lower calves seriously tightening up. Am trying magnesium and reducing caffeine intake. Trying to stick to a cadence of 180 steps per minute which has been very beneficial on my quads, and trying to keep my pelvis upright whilst running. Good times for my routine 15km runs, and the last 2 long runs have also been quicker than previously.  3 weeks until race day; 7 more days of tough running before starting the taper. Forecast so far is for rain on race day, which I'm quite happy with. I just hate racing in sunshine. Am hoping to better my 3hr20m from the Cadbury Hobart Marathon in January this year.