The GT won't get 50 extra HP and 75 extra TQ... the Ecoboost will... and even at that, won't exceed the DH numbers. Probably one of the biggest limiting factors for a FP GT tune is the DH itself... Ford doesn't want to "easily" give the GT more HP than the DH.
I say wheel bearing... Recently I had another car with whine/humming noise in the rear... dealer wanted to replace the driveline ($3000), but I knew that was just them throwing maximum dollars at it. A little more diagnosis on my own narrowed it down to the wheel bearing and the noise is all...
I think so... FP is probably unlikely to give the GT the same or a few more HP than the DH. Also their tunes are conservative... for 91 octane, not likely to make it worth the trouble for minimal gains.
Some will only post the first two digits in the third column... the last two digits in the third column are not any settings, they are checksums and will be different depending on the digits in that line, and will change on their own... so basically unimportant to the changes you are making.
I was a Camaro guy... have had many, and a couple firebirds... all gen 1, 2, or 3 (still have 1). Have had some other GM muscle cars as well. I was stuck in the past for a while and didn't care for Gen 4 Camaro, so built a couple old hot rods (still have 1). Daily driving Cadillacs for about 25...
For many years, rinseless washing has been my standard for cars that only go out in nice weather... I still like full rinse and water wash with daily drivers...
I still don't think that is the issue... easy way to find out, just change the angle of the radar sensor...
I too have had no issues with similar sizes. Though I did change tire size (rev per mile) in the PCM so speedometer would be correct.
Alright, enough of the high milers... Let's see who can get the lowest gas milage... I have a head start, I get less mileage than most of you GT owners... and I drive an Ecoboost! Game on!
Forscan is it... dealer "usually" won't do it... you can ask them. Any tuning shops near you? They may be willing to do the forscan mod for you. Or reach out to forum members that may be in you area.