Would I have a problem pulling a 38' Fountain SC with a 3/4 ton dirtymax? I would think it would be ok but the owner has a dulley and I don't want to drive half way across the country and have a problem.

How much does it wigh with the trailer?

you will be fine as long as its on a good trailer

I was thinking I would but does not hurt to check before I drive 20 hours. It is on a triple axle Myco.

As long as it has good brakes on the trailer you will be fine. Getting it going is the easy part !!!!!!!

Are you on stock size tires?

Sometimes when going larger you get a little tail sway from the extra sidewall

38 SC weight listed is 10,400 lbs but add 500 lbs for a generator.Possibly up to 250 gals fuel and etc?

This one has all the options so I am thinking it will be heavy. I know I will have the power but just the handling of the single wheel in the back.

Sounds like it should be ok

Stopping is the issue. Does the trailer have Electric over hydraulic brakes?
Did you look at the ratings here
http://www.offshoreonly.com/forums/t...er-thread.html

Let us know how it goes.

It will pull it, but you will be legally overloaded. Look up vehicular negligence in your state for more information. It's not pretty.