What engine would you use if this was you?

Sup gang. So Im in a position where I have an opportunity to purchase a 1999 Freightliner FL60 with 18K miles for sub 20K. Truck looks brand new inside and out and is pretty legit. Shes a 4x2 24' box truck with an extended cab sleeper and a 20K lb drop axle. I wanted to buy a truck similar to this (though brand new) to throw a 28 foot flatbed on it and run around the 50,000 GVWR range. Right now this truck has the factory cummins with the spicer 6 speed. That cummins is a good motor, but I would never dare to be grossing 50K lbs and try to move that with 160hp and a 6 speed. So this is where you guys come in. What engine and trans combo would you use if you were to swap it all out? I was thinking about getting a Cat C10 and rebuilding it to a 350hp spec and throw a 10 or 13 speed eaton behind it. Any other suggestions? Ill be running the east coast mostly in regional runs so I need something with good torque to run the hills here. Fuel economy is so so. I dont expect to get anything wild with a boxy freightliner but I'd like to find an engine and trans combo that can maximize that. As of right now I do not know what the rear axle ratio is so I'm flying blind there until I find out.

 

Correct. She appears to be the base line cummins running at about 160 or 170 hp. Im not 100% certain on that tho as I cant remember what the engine plate said. (looked at the truck a few weeks back and forgot to nab a picture of that)

I dont have any experience with the M11. Hows parts in terms of availability? easy to fix? Ima do some looking into the M11 and see what I see.

 

I can do that but Id rather not bump the engine straight to its max. Running like that Id imagine will lead to issues down the road. And like someone else said, cooling will become an issue at the same time. then again, radiators can always be upgraded lol.

Yeah i looked online and saw both. Seeing that Im remembering a 160Hp, Im betting that its the 5.9. I was going with the 8.3 like I mentioned earlier but I honesty wasnt sure. I cant remember what the engine plate was. But 160Hp would be pretty low for an 8 litter diesel.

Nah. The small cab dimensions is perfect for me with a straight truck. Plus shes already sitting at 52K Gross rating as is. That and the low miles for the price tells me I need to look into this truck. Trust me I would love a full size rig like that but thats not the kind of equipment I need.