50 mile per week is plenty to achieve your aim.
you can recover well and keep healthy and enjoy your running.
6 weeks
do 6-8 miles per day on the hills easy to steady for 6 weeks. do a long run of 12 -15 miles and take a day off. include 3 days per week strides of 150 m x 6 with full recovery, in the middle of end of a run is fine. recover fully, if you have 2 tired days in a row, take the next day off. when you're going good go hard up the hills, or at least steady.
6 weeks
then keep up the mileage and do 2 workouts per week something like this
6 weks
get a partner or group and run repeat miles at 5 minutes x 6 with 5 minutes recovery
do 4 x 600 meter hill workout with walk down recovery, and do this hard, where at 400 meters you are having trouble, and at 500m you feel done. recovery is walk slowly down the hill.
do the 6 x strides 150 m easy but fast 3 x per week, they can be used as warmup for the hill run repeats.
3 weeks
back off to 40 miles per week. - easy to steady depending how you feel.
3 quality workouts
12 x 200 m in 32-33 seconds with 45 seconds rest.
2000m to 2400 hard on the track, 5 min mile pace or better
6 x 300 m hill sprints hard with slow jog down recovery
go easy on easy days. and go hard on hard days.
find a group that has guys that do 1430 5k, and try and hang with them in workouts like these.
once the 5 minute per mile pace becomes ingrained, and habitual, you only need to hit the track healthy and you'll run that pace for 3 miles easy.
listen to your body and come into your quality days ready to hit it hard.
good luck, and this schedule should be a lot of fun.
if you keep track of the times, and you rest, your times will come down every week.