I am getting a couple of silicone hump hoses soon. They are those silicone couplers with one ridge in them (similar to an LS1 smooth bellow hose). My question is, what overall diameter am I going to need to get a snuge fit over the stock throttle body? How about the airlid (dual airbox iroc intake)?

I am doing this so I can replace the accordion style TB bellows with a nice smooth flow friendly section of 3.5" PVC piping.

 

The airlid is 3.5" diameter. Can't help on the throttle body but 4" comes to mind.

 

Ok - thanks