Is there any place I can buy an aftermarket tube to run with stock airbox, without buying whole intake and filter?
I do not want to modify stock tube or box.
Thank you.

 

You can get an AirAid MIT replacement tube from www.macromotive.com, they're about $107 for the tube. I think AirAid is the only company selling a replacement tube. A DJ motorsports tube will fit using a Fernco 3" plumbing coupling too. Summit sells them for about $190, then you could use the tube then resale the filter and heat shield to try and get some money back. I'm using a Volant tube with my stock airbox with a Fernco coupling.
Jim