I have no doubt that the OEM plastic piece is fine if one follows proper torque of the air filter clamps and don't hamfist it. But with that said and reading there were some issue with them breaking I thought why not spin one on the lathe and remove possibilities of that as a failure point. So here is my version of the sleeve from the air filter to the throttle body boot.
I am going to make a drawing for it so if you want to have your own made you will already have the dimensions and drawing.
Ex machinist so I radius everything unless called for otherwise.
Notice fancy bell on the intake side? Adds 20HP, Actually I am kidding but it does look better then square entry.
