Im in a similar situation, my aim is to dip under 85 mins, well capable on recent training runs but trying to work out how to run it,I'll be running Dungarvan Sunday. Have yet to push myself at the 10 mile distance.
I've been doing some good track running but I've slacked in recent weeks on longer weekend runs.
I ran a fast 10km about 3 weeks ago so at the moment my plan of attack is try that pace again, my big fear is the adrenaline kicks in and push it 10% too much and I'm goosed after 5/6 miles.
Might go with 3 miles sections at 25 mins leaving me with a bit of breathing space last mile, last 1.5 miles are mainly uphill AFAIR,