Can a 400HP truck carry 35K 53ft van load on steep grade easily?

As long as it doesn’t crawl to a stop and begin to roll backwards, you’re good to go.

 

Oilfield hammer:

 

If you want your drivers to be unhappy buy it. If you want them to be able to do thier job, not be a hinderence to other traffic, not be frustrated in traffic, stressed getting up to speed on the ramps buy something better suited to your needs.

 

Ok I'll move into this century lol...but it's fun to reminisce.
Currently running a 450 isx coupled to a 10 speed Manuel thru 3.42 rears , always 77 to 80k gross and run midwest to Pennsylvania and back ...it does the job.

 

Did you know HP and Torque are always equal at about 5200 rpm?

 

I'm impressed you got a big truck to 5200rpm. My tach only goes to 3k.

 

The HP will do just fine... That 2:47 is what would concern me.

 

I ran trucks with 2.47 when I did food service. They ran about 1250 at 62mph. We were always loaded to 80k and the safety guy said they were de nutted to about 375hp maybe 400 and progressive shift enabled. They were slugs. Pulling the hills from Binghamton to NYC at about 40mph. The newer trucks with dt12 they started spec'ing them with 2.64s instead and they got better fuel economy

 

5250 rpm