Adapter for bigger carbs to stock airbox for under $7

i did mine in a similar way, but cut the airboot back, put in a piece of pvc that was the same size as the opening on the carb, and then a coupler.
 
DO NOT go that route. Carbs work on a venturi effect, as the air passes over the jet it draws fuel... This requires velocity. In going from a small diameter to a larger diameter you are decreasing that velocity. This will throw your jetting for a loop........

LOL Touche phrags. I was cracking up looking at it. Great design.....bad idea. It defeats the purpose of even going up to a bigger carb.