Those Canadian trucks are on the high end of streetable, even with an ECM swap after the pull it would still be pushing it to run one with a loaded trailer behind it for any amount of time.
They also spend alot of time and money installing the shifting cogs out of the newer auto shift trannies in the old style boxes, they say they have more clearance so the shifts can be made faster. Most of these guys also do the uphill drags with trailers on.
There are only a select few street truck down here that run like that, being that some of them are putting between 1100-1400hp to the ground it almost puts them in class with the ostpa prostock class.
Also for the classes they would have to compete in down here they wouldn't be allowed to shift, at least it's in the rules for the super semis and the prostock trucks.