Bed rail system ?

Hey Rivian owners, future Rivian owners here! My R1T is currently on order and I’m trying to design a rear rail system and my rig.. does anyone happens to have detailed dimensions of the rear bed rail mounting locations? Specifically the distance between the forward and rear mounting point, and the distance between the forward pointing point and the back of the cab? Any out is greatly appreciated! Can’t wait to be apart of the club!!