My Fuel-Up light came on yesterday at 631 miles on the tank, DTE = 35. This was on my first tank full after modding the vent. I drove another 40 miles before pumping 36 gallons in. The first 35.5 went right in, and clicked off as I was finishing washing windows on the passenger side. I ran fuel in slowly, and when it clicked off again and after the foam disappeard, I could actually see the liquid level in the neck (duh, just like others reported).

The first fill up after the mod, the level didn't get this high cause I was in too much of a hurry. I thought it was full enough. Now that I can see the level, I'll have more consistant fill ups.

Historically, I've been able to go another 75 miles or so after the FU light comes on so I'm pretty sure I'll be able to have consistant 700 mile tanks now. That is if I don't continue with the occasional 80mph runs.