Pacing for longer events

AdsH
AdsH Posts: 13
I'm doing the Wiggle Magnificat on Sunday, I hope to do the full 129miles, a new distance for me.

Total experience - 3years with a few 100ks, some 80milers and a century. I've always been interested in time so tend to go pretty hard. This season II've done:-

Cotswold Classic 67m, 950m climbing, time 4.03, average HR 86% of max
Princes Risborough Sportive 84m, 1.6k climbing, time 4.59 average HR of 89% of max (that hurt!)
Bucks Off Road 84m, 2,260m climbing, time 8hrs, average HR 83% of max

Winter training was mainly long and slow intersperesed with VO2 max. I've done a couple of 80m mtb rides at low intensity and can now do 40miles in zone 2 at 15mph on the road bike. If I am really careful I can do this without getting over zone 3.0 but my butt hurts by the end.

I really don't think I will make 129miles in the sort of aerobic/anaerobic pain I have done for the shorter events. I think the MTB stuff shows I can spend 8hrs on a bike.

I'd like to finish in a good state and in 9hrs. To this end I plan on

I will start slow - I really will
I will not ask anything from my legs other than to rotate at 90-105rpm. I have a triple, my Granny is my friend
Most of the time Max HR zone 2.5ish - 60-65% feels good
Periodic periods out of the saddle and try to keep HR down
Coast downhills (something I tend not to do)
Periodic stretching
NO DRAFTING - no-one is going to be going up hills as slow as I plan to and I will burn myself out if I draft.

Can any of you give any other tips or confidence booster I sort of have a bit of mental block on this.