I drove around turkey bay once in my mild XJ and there certainly was a whole lot I would not have been comfortable trying without some people to rescue me, lol. Seemed like a nice place.
There are plenty of good free back roads in the park too, frankly. Some of the 3XX and 4XX roads are pretty much 0 maintinence. Bring a chainsaw if you try to go down 412... (off of 319), I never made it to the end. We camped at the end of 319 instead (absolutely the prettiest camping spot I have ever been to).
Getting to the spot we got dirty