85 cc's is the stock volume but it varies some from head to head (not precise).
The early heads if your speaking of your 03 stock heads, max lift is around .510.
The later heads with beehives can go .575-ish
If your talking 03 heads, they'll need springs at a minimum. If your pulling them, pick a machine shop and discuss your goals with them and go from there. Lots of good guy's out there. Don Dorfman HD Street Performance, Scott Palmer Hillside Cycle, Kirby Apathy Vee-twin Performance.