The OD is slightly bigger. But, the 75mm Big Bore Throttle Body Kit works great with all stock diameter intake tubes. The stock sized coupler will stretch over our 75mm Throttle Body unit. You just may need to warm it up slightly by leaving it direct sunlight to make it more flexible. Also, if you coat the inside of the coupler with a couple drops of engine oil, it will help it slide onto the larger throttle body easier.
The VQ35DE engine responds really well to a larger intake tube such as a 3.5" or 4" diameter. But you will still see noticeable HP gains if you install it with a stock 3" intake tube. Anything you can do to help this engine breath easier, the better.