2008 sportster heads?

[BB]

I have a customer that wants to install cams in a 2008 sportster . My question is what lift do the heads stop flowing at ?What is a good choice of cams .And if I increase valve size whats a good cam ?How much can I mill off heads or just install pop up piston?Looking to make a good all around street bike.Thank .

[deathwish]

not sure about sportster heads but Twin cams heads when ported show very little improvement past .550 lift. Improvement is fast and easy to that point.