Thats not true, the 65mm is better all around for a N/A, mild street motor, regardless of intake opening size. If the TB were bigger than the intake opening, sure,you would have a problem, but being smaller makes no difference that you will notice, and the increased throttle response of the 65 mm TB is preferred.
And the trick flow opening is 75mm I thought?
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1993 GT/AOD
'93 Mustang GT