Good job. Let us know about the adhesives test.

Well I narrowed it down to two options. A company called Reltek Makes an adhesive B-45TH which bonds Polyethylene. It has some elastic properties to adsorb shock and vibrations. The smallest size they sell is $100 and is more than enough for one airbox. Tap Plastics sells a system called Poly-weld which is what I decided to go with. The box has to be flame treated with a torch first and there are some specific instructions for application but it is an actual chemical weld. It wont be as resistive to vibration but it should hold better during a backfire. Poly-weld is half the price as well. I did order loctite 3030 but im not as confident in using it on the airbox. I will follow up with results in about 10 days.