There is an easy way to figure how fast your truck is at top speed.

Draw two lines 100 feet apart. You'll need room on either side of the lines for braking and to reach your top speed. Do it on a nice level road. Then you'll need a stop watch and someone to time you. Get your truck up to operating temperature and do a run. You want your truck to be at top speed when you hit the first line and continue until you hit the second line. Get that someone to start the timer as soon as your truck starts to cross the first line. That someone will have to stop the timer as soon as your truck starts to cross the second line. Do it a few time. This will allow the time keeper to get some practice on the timing. Then, do it several time in both direction and record each time. Now, with your calculator, take 100 divide by your average time and multiply that by .68 and it will give you your speed in mph. So if your average time between lines is 1.8 seconds then it's 100/1.8x.68=37.77 mph.

Post your results here and include what your mods and hop ups are.

Oh, and try to be honest.