If your talking about the factory race pipes save yourself some headaches and stay away. Their loud and finiky up high.
Talk to Mott's Machining about a set of Crank Shops, Tom seems to know the magic port timing to get them to run up high.
Personally I'd put all that money into a big bore instead, after the pipes and porting you'd need to get them to run for a couple hundred more you could have an 840 and it'll be more reliable.