Just becase you "can" doesn't mean you should. I would never tow a 3/4 ton truck on a car trailer with a Taco - it's way more than the Taco is designed for.

Your trailer is probably 1200-1500 in itself, so that would mean that your mud truck would have to be under 3500# to be w/in Toyota's tow rating. Given that most mildly built Toyota 4Runners are over 4K lbs, I'm going to guess there's no way your truck is less than 4500# in and of itself. I'd be willing to bet that your trailer/truck combo weighs in at over 6k#.

Even if you can get it up to speed, your brakes simply are not designed for slowing this combo down.

Do people do i? Yup. I've done it myself and it was the scariest 1000 miles of my life. I'll never tow more than Toyota recommends again...

One other thing - if you are over your towing limit, you may run risk of legal issues and insurance issues if you have an accident; If you're over Toyota's max weight, then get in an accident, your insurance company and cops and say "hey, he was doing something in appropriate!"...

be careful.