I am installing a ball hitch in the 8' bed of the truck and need to know how close to the center of the rear wheels I can mount. Can I install it vertically to the center of the axle or should it go a couple of inches forward? The gooseneck is 67 inches long. Also I have a ribbed bedliner in the bed, can I install it directly through the bedliner or should I remove it. The ball is welded onto iron brackets that will bolt down to the bed.