I just finished a "drill and fill" and installed 4" ports in front of the fwd pylon. Buy a Dremel tool and a spiral cutting bit! I bought my Dremel (420 series) a few months back and it has been one of the best power tools I've ever owned.

Be forwarned...there is a double layer of glass that adds structural strength in front of the pylons. It would be best to install your ports in front of that. I can measure mine and tell you how far forward of the pylon if you like. I cut through a small portion of it when I made my holes for the ports. My plan is to see how it works over the summer and add a layer of glass inside the hulls around the ports if I see any flex or stress cracks.