The pickup in the Crusty flatty had that tube. It was a military 99 engine. The replacement filter element had to be stretched and reshaped to clear that little pickup tube. I show it in one of my videos. (not very well).
https://youtu.be/RDTKXf18wyU
The pump and pickup (now I think about it having watched the video) came from a UK 21stud truck motor.