If you have to ask the question....
Seriously, you got the best answer here:
https://www.ford-trucks.com/forums/1...l#post10212521
You could even build the 360 into a 445. With mild compression and the right cam in that engine, it would drink gas like a 401, but have more power than the 534.
As for your plan to tow a 53 foot, 18000 pound trailer with this thing, well, I hope you have at least $2million in liability insurance.
Regardless of all the stuff you've attached to that F350 frame, it's still an F350 frame.
Must be a full moon again. Ever get this resolved?
https://www.ford-trucks.com/forums/7...96-ranger.html
With the economy the way it is, there are lots of running medium duty trucks that would do the job SAFELY.
Knock yourself out if you must....