For awhile I kept mine in a 55gal even when he reached 6ft.. then I switched him over to a 40gal breeder which he loved cause he could coil up looser, now I have him and my female in a custome tank I believe 5'long 2.5w and 2-2.5' t. and I'd say they don't mind that tank at all.

As far as books go you can never no. because of the fact that people power feed their animals to make them girthy-er faster and even longer, my male rtb is about 7ft and my boyfriend had him for about 5 yrs. the female we just got and she's about the same but i have this feeling shes younger....only because usually feamles are 2x bigger than males even just a few yrs apart.

What size is your inclosure now?