If the guy with the 7000 pound truck only has 600 hp, my calculator sez he's going to be running 13.89 @ 97mph. It would seem to take about 750 hp to run a 12.89 @104...... Think somebody was maybe pulling your leg a bit about the quarter mile time, or else they got a gadzillion dollars in that dually to get that diesel to make 750 hp!!! Not saying it can't be done, but it would take some really trick suspension and slicks to get that pickup to hook up the 750 hp enough to get it in the 12's!!!! JMO