I need to know the width of the bed in my F150 to determine which headache rack to buy, but i have the canopy on it right now so i cant measure it myself. I need the bed rail-bed rail width

Thanks yall

 

just got a camper shell/canopy the other day. it was listed as 72" x ?99?". didn't measure it myself, but if there's a 72" option, i'd get that

 

Damn i shoulda known it was too good to be true... the one in the pictuire is on a 97-up F150 but there were 2 listed i was hoping the other would fit my truck, no suck luck, the widest is 67"
Heres a link to a picture of the rack i had been checking out in case anyone else is interested for a newer truck, i was drawn to the top bar which looks perfect for mounting lights on.
http://www.haulerracks.com/html/truck_10.html