If I can be brutally honest mate, I'm baffled by your approach to training! If your target race pace is 8:30, your LSR should be a lot slower - more like 9:30.
What's the rationale for all these different paces? Are any of them at threshold? Any intervals?
You can make yourself a lot faster if you make some simple adjustments to your training.
1) Weekly LSR should be in aerobic HR zones.
2) 1 threshold run per week for 20-40 mins (no more).
3) 1 interval session per week.
4) All other runs should be easy (aerobic) pace.
5) Strength training 2 or 3 times a week is an optional (but effective) extra.
Are you using a Garmin 235 or similar? I think that this is key to running in the correct zones.
If you're on Facebook, you're welcome to join my London Marathon training group where (mostly) good advice is given:
https://www.facebook.com/groups/183684272425375/