I am feeling much more confident about doing 1.30 on Sunday. quote]
Even(ish) effort is the key, imo.
You need to average 6:51 to break 1:30.
I'd do the first mile in approx. 7 minutes - preferably
no quicker . . . . . . . . 7.10 would be fine. If you are running 'within yourself' and get through the first few miles feeling fine, then you'll gain
considerable confidence. It is a great feeling to be running at a fast (85%) pace (but
not flat out) and knowing that there is more in the bag.
There'll be
plenty of time left to make up the 'lost' seconds. In many half marathons, I've been overtaken early on, by people going 'hell for leather', only to overtake them a few miles further down the road. Some people will sprint off at the very start of the race, as if they are going to lose their place in a queue . . . allow yourself a wry smile

, as you overtake them 10 - 15 minutes later.
From three miles until approx. ten miles, I'd 'sit' on 6.50 per mile. IF at this pace, you feel great,
I'd still hold back until 10 miles. (If you are 'struggling' at ten miles, then you probably aren't yet fit enough to beat 90 minutes).
If you can get to 10 miles in good order,
that would be the moment where you should inject some pace. Most people 'struggle towards the end of races; if you speed up and start passing other runners, it'll give you a lift, when you most need it.
If it is windy, take every opportunity to 'hide' behind other runners - even if the pace is slightly slower than you might wish.
Oh yes, some other runners do otherwise, but I have always worked on the principle of concentrating on just
one mile at a time. Take your mile split times - it is easiest (imo) to concentrate on
individual mile times - thus breaking the race up into small, manageable chunks.
All lot will depend on the weather and the course; but go prepared with a fixed game-plan and you might surprise yourself.