Had mine up to 120 briefly end of last summer and it was pulling hard. Boy was that a little scary. Front end starts lifting at 90 and contiues from there. Steering gets floaty...etc Still handles better than my fathers '09 F-150 at those speeds. His gets scary over 85 where as mine gets that feeling around 100. Just a big heavy vehicle to go that fast on a continuing basis. Can't steer if something were to happen.

Vibrations..likely from pinion angle. My mustang would do it lightly at 90-100 and get very noticeable above 120.
Pinion angle changes from lifting/.lowering, weight in the bed...etc
Going that fast can lift the front up which pushes the rear down and can cause improper pinion angle.

 

Well I really dont quite know to be honest, the speedometer was pegged, speed limiter on my DSP was set to 190mph.... so somewhere in between 120 and 190...

(not on a public road, on an abandonded air strip, about 2miles worth of straight paved road in the middle of the desert)

 

DSP doesn't tell you? get a GPS and see if it shows up on there

 

you all are bad influences! speed past a cop today going 105 ... ruined a pair of good jeans. how/why i did not get pulled over is beyond me.

 

About 110, don't really pay much attention to the speedo though. Not at that pace anyway. I'll see what I can hit tomorrow

 

A little under 100 passing someone, I try not to go over the speed limit.

 

118mph and she had nothing left to give

 

90 Cruising to Vegas, Felt smooth and responsive the whole way. Nice tail wind on the way there, and this was all before the gear swap so I wont be doing that again (RPM's would EAT up my gas) I think I was at about 1900-2050 rpm with the stock 3.21 gears at 90 too haha.

I'd love to have a WOT run to 100+ but haven't found a spot or reason to do it yet. Won a few Light to Light runs though

 

Faster than the two-digit interstate numbers (I’m from the northeastern part of the US, so all the interstates around here are 80’s and 90’s).

 

Ok, guys now lets hear how nice a lowered well engineered suspension would have felt at those high speeds.