jenko
+1y
I had mine made, they sell such things as a weld on/bolt on product though.
X height, Y diameter etc etc.
It's the cheapest way to go, buy them prefabbed and weld them on.
If you're building the intake, are you doing it yourself? If so it'll be a doddle for you!
If you can't find some, talk to a fabricator/metal spinner (turner) and they'll make you up some.
They can also be pressed.... get a piece of tube and a press, fit a tow ball and press it into the pipe... rough as guts but it's a stack too