I think mine is around 104, but for previously stated reasons most people have no business being up there sucking up that much fuel. I did it on an open stretch of 3 lane interstate, with no other cars nearby just to see...I doubt I will ever be up there again. My previous truck, Ranger, had a limiter of 92.

 

with the right suspension mods and proper speed rated tires you wouldn't beleive how well the f150 performs at 120

 

HI!... I've had mine up to 154MPH and it was as stable as if it were at 50MPH. I could let go of the steering wheel and it went perfectly straight. But I was also lowered 6.5 inches in the rear and 4.5 inches in the front, had front/rear sway bars and 295 front, 305 rear "Z" rated ties.