If I remember correctly I went with this barb
https://www.amazon.com/gp/product/B0...e?ie=UTF8&th=1
Then street elbow to connect to the intake.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Don't bother with anything other than the street elbow. Real estate is at a premium at the back and you don't want to keep cutting into the firewall any more than is absolutely needed.