I have a pipe rear bumper with a receiver hitch on my FJ40. Right now out of expediency it is bolted on with the same bolts that held the bumperettes on, with four brackets mounting to the rear member in the stock holes. I seem to remember somewhere someone suggesting drilling these out and replacing them with larger bolts. Any body got any suggestions on what size to use? 1/2 inch will not fit through the bumper bracket holes - 3/8 will - do you think eight 3/8 bolts holding a bumper on would be stout enough to pull a largish fishing boat? Thanks for any suggestions.