If you want to know how much horsepower your truck is really making,
take your truck to the local drag strip and run it down the 1/4 mile
"test and tune" The MPH from your 1/4 mile time slip tells you the story.
now go weight the truck w/driver at a truck scale or junk yard scale.
Horsepower ='s .(00426xMPH x .00426 x MPH x .00426 x mph) x weight.
The is net as installed horsepower
Just like how a new car is rated.
For gross dyno brake horsepower
use .0045248 instead of .00426 in the calc.
Most full size pick up trucks weight well over 4000 lbs.