No way would I tow that trailer, with three horses in it, with a half ton. Especially an older/antique one. Just because you *can* doesn't mean you *should.*
Let's do the math:
The trailer itself weighs at least 1500 to 2,000 lbs. Three horses (assume Quarter Horses, yes?) at (on average for a decent quarter) 1,000 lbs each is another 3000 lbs. Throw in some tack, supplies and other miscellaneous and all told, you're up to about 5-6,000 lbs. Some of the new 1/2-tons are safe with that, but not an antique one without significant modifications. 1st time someone brake checks you on a wet hill and you are going to have a really bad day.
I'm not sure I would feel comfortable towing *anything* with a truck smaller than a 3/4-ton rating.
