My dune port gets about an hour of run time in the dunes with the stock gas tank. I'd stick with your T5's, they'll match a dune port very nicely. If you want new pipes, CPI's are better for all-around riding, they have more midrange then the shearers (i think, someone correct me if i'm wrong). If you do get an aftermarket tank get a Clarke 5.5gallon, they look much better then the IMS, and i think they are on ebay for like $185.