A couple things to check.
1) Ferry at Cameron - I don't know what their weight / length limit is - but my memory of the entrance / exit from the ferry was a sharp dip where my Chevy Venture van dragged bottom slightly.
2) Drawbridge at Mementau River. Steep and a 7 ton limit if my memory is correct.
We attended a wedding in Grand Chenier back about 2000 - so conditions may have changed. I understand Hurricane Rita in 2005 hit the area very hard.
From Port Arthur to Cameron is travel through a high grass wetland. There are some side roads to the Gulf - but you can't see water from the road most of the time.
Cameron is a very busy for the size oil service town. Stop there for lunch - no other place to buy prepared food until you get to near Abbeville.
The drive farther east is through some great wetland forests. Duck hunting in winter is a big deal down there. Grand Chenier is a few stores and a few side streets with homes along the road.
As mentioned above - it is all two lane with no shoulders. Don't expect to make the trip averaging above 30-35 mph.
