Which beggers the question - What is the 90mm throttle body actually DOING for you? What little research I've done leads me to conclude the 90mm TB is pointless unless you have a blower. I was hoping that perhaps the 84.5 might offer some real performance gain for NA 5.0's, perhaps with the Boss manifold. Hmmm, anyone?
I have seen his before and after dyno results with the 84.5mm accufab and he gained a minimum of 15 wtrq and as much as 20 wtrq and 20 whp in the midrange around 5300 RPMs over the stock throttle body. After 5400 or so the gains are much smaller at around 2-4 whp so peak gains are not massive but overall there is a much larger area under the torque curve. For a DD car those midrange gains as well as throttle response gains can be felt and are much appreciated IMHO. Even for someone who drag races the recovery from each shift should be faster vs the stock throttle body.