i noticed my stock TB measures 76.2MM wide, outer diamater. so rounding it to 75 MM
how does a 70 MM tb add 10 HP?
I doubt it would really give you 10hp. But being that you have a larger tb it wouldnt do you any good if anything it would hurt you if you made it smaller!
It might give you some if you went from a 60mm to a 70mm
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When the people fear their government, there is tyranny; when the government fears the people, there is liberty.
--Thomas Jefferson
I don't know what you have but my stock one was 68mm roughly. I have the BBK TB and there is no difference that I noticed. Maybe your measuring device is wrong?
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2008 Dark Candy Red V6 Coupe, 18" SSE Wheels w/ Falken shoes,8" Shorty Antenna, SPEC Stage 1, Airraid CAI, 8.8 w/ 3.31, dual Vortech turbo exhaust, LED Projector Headlights, BBK shorty headers, SEIBON Carbon Fiber heat extractor hood, Sparco Hood Pins, Kenwood 7" touch screen nav/dvd, dos 8" rockford fosgate punch, SS window louvres, Midwest plenum cover, LED taillights, 93 race tune from bamachips, Personalized license plate "GOFASTR" (adds about 15 horses for the license plate) 220hp/232torq
did you measure both sides of the stock and bbk throttle body i noticed that my stock throttle body was smaller on the intake manifold side that on the CAI side check the measurements on both sides of your bbk throttle also another measurement you could check out is the flange it could be bigger that the stock one or have different angles
2005 Mustang.BBK or Stock TB? 
