just curious what size is the hole in the upper plenum exactly. I am going to install a 73mm bored throttle body and need to know if I need to put aside enough time to pull the upper plenum and port it out. Thank you to whoever anwers this question accurately. by the way its on an 03' non rev up.

 

I happen to have a plenum from an '03 out in my garage. The best I can measure, the opening is 72mm.

 

the opening bottle necks a little right after the opening. would not take long to pull it off and open it up and remove the bottle neck.