There have been a couple of threads recently about towing M105s, but I’m not going to try to find them; I have school work to do. Basically an empty M105 weighs in at 2700 lb., easily handled by your F250. As you can see in the pictures below, they can be towed EMPTY fairly easily. That empty trailer with no active trailer brakes was right at the limit for the Bronco which doesn’t do well in a panic stop, anyway.
As jeepin points out, the tail end of the trailer might be a little high for legal limits. In two 95 mile trips pulling M105s behind my Bronco with the trailer’s posterior stuck up in the air like a baboon’s butt, I was passed by several state and local police. Use stick-on lights and you should be okay.
There are 2 solutions to the trailer height, 1) Turn the lunette over, that will give you about 5 inches and 2) use some type of hitch that raises your pintle. I didn’t do either and my hitch is probably lower than your F250’s, so that is probably worst-case. You might want to consider a permanent solution if you are going to pull your M105 with your F250 in the future.
A friend, Bushman5000, recently pulled an M105 500 miles from Ft. Riley, KS behind his Jeep Cherokee with no incident. He found that dropping the tailgate so that it didn’t form an air dam made it tow smoother with much less drag.
If your trailer is of the newer persuasion and has an air tank and relay valve, you will definitely want to drain the air tank before you start. If they have any pressure, they can lock up your brakes for you, thinking that it is an emergency situation where you have lost your air lines. It could have low pressure that would not set the brakes until you hit a good bump.
Good towing and welcome to the M105 faction; I have 2 plus an MKT-85 and am eyeing another M105 in a farmer’s field.
Arlyn