Thanks Pappy.
Elktracker, I've made probably 8 bows like this. If the tillering goes smoothly they take around an inch, I've found. I don't even consider it really, because bows like this can be very healthy and keep there speed even in really hot humid conditions.
Even my first one that was about 3/4 an inch wide and 65" long, backed with a maple board is still shooting really well and has over an inch of set.
Hope yours turns out great.