I kept a guyana bcc for about 15 years before gifting her to my a good friend who had always wanted a boa. When I got her she was close to neonate size, when I gave her to my friend she was 11ft 4in. Fed her weekly for the first 2 years, then once a month after that. Prey was about the thickness of her body. As an adult I was feeding her rabbits, not sure on the weight, back then I was not as precise as I am today.
I saw her last month and at 17 years she is looking pretty good.
Btw, anyone even know how long they live? I had heard about 15 years but apparently they can live much longer. Lol