To best simulate the feeling, back the truck straight in to an immovable object at 5 mph (concrete walls are great for this). It will probably do less damage too.
Truth be told however, assuming the drivetrain survives the launch, it will be winding a 315hp v8 through 4 gears within 40-50mph. I don't even know that the engine and transmission could keep up.
The only experience I have in this area is 195hp of Vortec V6 in my mom'* '95 blazer. Even then, downshifting to first in 4 low is like hitting a brick wall, and that is just from idle in second.
It really is a very bad idea, but if you decide to do it, please take a video of it, because youtube needs more fodder, and I enjoy a good carnage show.