MetroNYC's truck has the Gen.3 compressor, 65mm Ford Racing TB, 80 lbs. injectors and Headers.
That is the same you have now, right?
The GT 500 is a 60mm TB, it's too small and wouldn't work with the Tune (they built for MetroNYC) you wanted from JDM.
Actually you can interchange the GT500 twin 60 and CJ twin 65mm with our tunes. It's just going to limit or improve power depending which of them you swap. Aftermarket units like the Whipple throttle body are inconsistent and often cause tuning issues which is why we only use the Ford units.