Yeah, was a little concerned about that, but I figured the truck by itself and just one car wouldn't have a problem, with 505 - 527 lbs of torque, my next question was going to be, how do you turn the pump up to get a little more power without going overboard and melting the pistons, or washing down the cylinders ? I remember back when I was young there were guys with these old B models running like mad with the pumps turned up on them, I had a fast "80" Pete, I was running late to get loaded, and was running about 90, I saw a sparkle in my side view mirror, looked and I could make out the unmistakable grille and headlights of an old B Model, he was coming down off a grade on 27 coming into Clermont in Florida, and he was gaining! Lol. I put my foot down into the pump hard in my 400 Cummins, and it was turned up A LOT !, and pushed it up to 97, that's all she had, we started pulling up a slight grade, I figured, "he'll drop off now" ...............NOPE !! He kept gaining, by now I could see it was a beautiful old B61, Not even a B73, or 75! All I could keep saying to myself was "WHAT THE F@CK??!!" Lol !! When he finally got up alongside of me, there was an older man, looked to be in his early 70's, and that Mack was a beautiful red, chrome grille, chrome bumper, twin chrome 6" straights, Full chrome rear fenders, and lots of other chrome, and it was barking louder than my 400, which had straights also, and man it sounded SWEET! All I could figure was it must have had a 300 stuffed in it, but couldn't figure out how the hell he would cool it if it did! He was pulling a dump trailer, and it was a SINGLE AXLE tractor !! He just smiled at me, shook a finger pointing straight ahead of him, and motored on by! I won't forget that till the day I die! Lol ! I also remember my dad telling me in the old macks, I guess the LF's and LJ's, that they would tie a wire on the rack on the pump? He said when they were pulling a long, or real steep hill, they would pull on that wire, which would open the rack, but he said you had to be careful or you could blow the engine if you held;d it too long, or too far open. Maybe that was the Lanova engine? But, I figure if I can turn that pump up just a little, it would help, plus I'd like to see the fire come out of the stack at night! Lol "stacks" eventually