If you put the OS .18 in there, it will be quicker than pretty much anything you will come across. The FF with the NT.16 will do 40mph or near enough, with the OS in there you would probably be up nearer 50!! If you are going to race your truck, I would advise getting the aluminum brake seat, New Era models roll bar, Dr Honda shock towers (if available) and two pair of front buggy shocks. With the OS engine it might be a good idea to upgrade your diff gears to the hardened steel ones and get the cnc machined diff hub. Switch out the stock servos if you haven't already and go race.
EDIT..........Search the thread on the diff cup modification and do that asap!!