Hi Joey,
I honestly can't remember where I got the tube as it was over 8 years ago. I know that Buds Classic Cars has them along with a lot of other great parts:
https://www.budsclassiccars.com/catalog/. It could have also been Carl's Ford Parts? I will look in my receipt binder tonight. There are quite a few threads here that discuss this topic in detail. Many have used a Chevy BB tube.