We stayed at My Old Ky home state park in July of 2011 and had friends with us who had a rig as long as yours. I would suggest you try for space 21 because as you enter the park you will need to make an immediate right to go around to the back of the park. Because of the length it is tight in several of the spaces to the front and the angles are a bit steep toward the front of the park but you should be able to pull up the drive and back in fairly easily to space #21.
My Old Kentucky Home We had the best time at this park and you will too! Also if the wife is into wines the way us wives were you can do the Bourbon Trail and combine it with the Ky Wine trail like we did! We had a blast! Also check out the museums there in Bardstown, wow what history!
Sheila aka....