I did a run last night. Didn't want to blow it up sooo I ended my pull in 6th. Gear was fading out right at 132mph. :/ My friend was thinking that it was limited by air/fuel mapping as we did not feel any "cutting out" or fuel shutoff.
Next time I'm going to try in 5th and see if I can get a peak at the 140+ mentioned by VTMARS.