Ive read a few guys that have swapped in the 465 lph walbro pump by modifying the stock hanger. They few guys that have done it, cut off one leg of the hanger and shortened up the other, and then clamped the pump to the hanger. Should be enough pump for anything you have planned in the future. I think the biggest issue possible with that setup using stock lines, would be controlling the fuel pressure if the stock return line doesnt flow enough. If your fuel pressure drops, that indicates not enough pump or a problem in the fuel setup. Remember, for every pound of boost, you should also be getting an extra lb of fuel pressure, assuming your using a 1 to 1 fpr. With a base of 43.5 and 13 lbs of boost, your pressure should be around 56.5 lbs. The fuel squirt from the injectors needs to overcome the added pressure in the cylinder. If you have enough pump, you can actually rasie your base fuel pressure to make the injectors think they are bigger, but this would require a complete retune. It would lower your injector duty cycle though. Increasing your pump voltage also may gain you some extra fuel flow, but they aren't cheap. I personally believe its money better spent towards upgrading the pump or fuel system itself. This link has some great fuel injector calculations.
http://www.witchhunter.com/injectorcalc1.php
