I had the same truck, 550 Cat, 18 speed, 3.25 rears. 07, 379 (bought it from Dino at Western in Denver) I was on 95 in Nevada, slight downhill, no wind, flat out with no parameters my GPS said 108 MPH. I think it was around 1900 RPM.
Are you sure this wasn't in kph? Hell in that case my truck does 180...up hill...in a snow storm....through traffic..beat that!
Yeah trucks can, but steers blow out and it would get messy in a hurry. love that " eastbound and down" up above me.
Oh Auto needed them and hip boots for most of this post--here's a hint look at the posts?-then match up posters age and supposed time driving and it gets really deep really quick--but to clarify 1 thing about couple of my truck'll will run 130 etc...depending on the ecm in a 6nz for example--if it is programmed w/out a speed limiter--ie:the menu setting that asks to program top speed--if u put in NO the default setting is 129mph&hp rating--gearing and granny have nothin to do w/it---just the # theputer defaults to---so yes of course my truck does 129 mph--the puter says so! Just sayin