not sure what to do?
Adjusting the throttle blades to give it more idle air defeats the IAC distribution circuit IF it actually works on your TB some earlier ones were seals later ones are not.
If going 52mm I would strongly encourage people to use rebored stockers to avoid these issues, and when going 58mm educate yourself on how to deal with them.
Far as the intake openings most seem to be 52mm but a few folks have measure 54mm so there may have been some variation but certainly not 48mm as one guy suggested.
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