Rear end help, 390 or 370 hauling cattle.

I have never had mine flat out, but I know for sure it's fast enough

 

3.22s to 24 talls behind a 400 cummins would absolutely haul ### at the lowest rpm you would want to pull it down too.

 

Honestly are big cams to be kept around 1800 rpm for best performance, and fuel economy?

 

I've always heard they were supposed to be 1900 to 2100 and really bad stuff happens if you drag them down to what must've been 1100 or so.

 

That's what I've read.

 

Yea my dad was used to driving his n14 and he bought a pete with a big cam in it, the first time he pulled a load with it the teach wasn't working and he ended up cracking a liner off just below the bottom o ring.

 

I know where I can get a blown up 400 big cam. But was told crank was snapped. So not sure it's worth rebuilding, VS parts.