Montana, I'm SOOOO envious of those straight, reasonably flat roads you have out yonder! I have NO doubt that you easily did 150 & with all the mods & tinkering you've done over the years, 185 should be doable!

165 is the fastest I've had my SRT at: Hwy. 156 east out of my hometown here in WI on a warm August afternoon. And, no, I don't have any "documented" proof because trying to take a picture of my speedo while rocketing down a 2 lane highway is even crazier than driving at that speed to begin with. Both of my hands were on the wheel so tight you would've had to pry them off with a crowbar & WD-40. It started to float over that stretch of highway at that speed so it was time to stop proving a point & start braking.
And I'll never have a passenger in my car while driving at that speed, either.
On the other hand, if any doubters would like to take a road trip up yonder & have a their life insurance policy good to go ....