For a BP thats all you need.. I myself use 4' for each because I enjoy watching them climb and stretch out ect... Some people act like a Shoe Box is good enough but in 29 years all my snakes have enjoyed a full 4' as long as they have good hides and fake branches & vines to climb on. For young BP's though that T10/T8 enclosure divided would be good for a couple years as there young anyway.