Engine 1999 GT - Throttle Body/Plenum Mismatching Bore Size

[Snazzyduck]

I was looking into aftermarket Throttle Bodies and Plenums for my 1999 Mustang GT. Would there be a problem if I had a Throttle Body with a smaller bore size than the plenum. I don't expect any flow or engine issues, but maybe some has experience with this or insight to add? Any banter is welcome, even if you're not necessarily a car 'expert.'

 

[General karthief]

I will respond with this suggestion, I would find out if there is a spacer that is 70mm and open the back side up to fit the 75mm intake opening. Just a suggestion. Although the miss match may not matter since it is just air into a plenum

 

[Noobz347]

You are purchasing both items? Why would you not purchase them in matching size?


I cannot think of a good reason to install a throttle body with an opening that is smaller than the plenum can accommodate.