Old Doug is exactly right. With 13 speed and about 250hp you can move the things you mentioned. One question , is it a tractor , single axle or tandem and what kind of trailer are you pulling? If your like myself , I don't want a 500hp motor when I run unloaded 60% or the time. I'd run it until you find something that suits better and use time as an advantage. The one I had was a N/A at 175 hp according to the plate. I cranked the fuel up till it started black smoke and backed it of till it put out a little black smoke. Supposedly this would be 210 hp. We ran it several years , it did blow a head gasket , cost 1500 bucks to fix. Basically surfaced the heads , grind the valves , new gasket kit and was back on the road. That's not bad considering how long we used it. As far as speed , I don't get in a hurry moving equipment anyway.
