Get into 3:30 marathon shape in 7 months?

Your 10 mile race indicates a 3:43 Marathon and that is considering Marathon training.

So you have your work cut out until then.
Train 30-40 miles per week and have at least one Half Marathon 6-8 week before the main race.

And a couple of 18-20 mile runs if possible.

Good luck.

What was your training prior to last week's race? If you ran that with little training, then seven months is plenty of time to extend that pace to 26 miles. On the other hand, if you've already been running 60 miles per week for the past year, then it might be challenging.

My experience with a similar goal: A few years ago, at age 57, I had been running only 4 miles once or twice a week and decided to run a marathon less than two months away. I bumped my mileage to 30 a week, including a long run, and ran 3:26 (7:51 pace). That was my first marathon in 14 years, but the 25th, lifetime, so I had some experience with the distance.

Wow that’s amazing! Only 2 months is so quick.

I’ve been running for about 3.5 years now. My weekly mileage averages around 30. I’m definitely a runner who thrives on lower mileage with high quality workouts. I’ve run 5 marathons before with my most recent being NYC in November. So this 10 miler wasn’t a challenging distance by any means but the pace was definitely a pace I’ve had to work for over time. I’ve only recently started to see how the 80/20 method really DOES work. So hopefully the progression will continue!

Here's my weekly mileage (and longest run/pace) for 10 weeks. Eight weeks out was when I decided to run a marathon. Long runs and recovery days were the two main ingredients (I never ran on consecutive days and no workouts).

4
11
33 (18 @ 8:18/mi)
31 (20 @ 8:18/mi)
28 (15 @ 7:42/mi)
33 (23 @ 8:48/mi)
42 (20 @ 7:52/mi)
26 (15 @ 7:30/mi)
18
4 plus Marathon @ 7:51/mi

The following year, with higher mileage plus workouts, 3:07 marathon at age 58.

This year, at 62, I'm back to 3-day-a-week running. Was hoping for 3:30 marathon next month. In February, 10-mile race was 8:11 pace, so I thought there was a chance. But it's not looking likely. Maybe 3:45. Ugh.

Good luck in your quest.

Grab a copy of Advanced Marathoning by Pfitzinger/Douglas and get to work.