Motorcycle Repair: Increasing HP/torque on a HD sportster, hi performance, compression ratio

Question
My bike is a 1997 sportster 883 converted to 1200cc using dished pistons and the original 883 heads, resulting in 9.25:1 compression ratio. It also has SE air filter and SE slip on mufflers. Presently, it gets 62-64hp and 70torque. I was thinking about having the heads ported, etc, to increase hp and torque. I've read that some shops can do this, with results of 78hp and 78torque for around $700.
How much of an increase could I get if I just had the compression ratio increased?


Answer
What you need to do is get a new set of heads, Your heads have smaller valves then a 1200. And even ported that do not flow well. I would get a set of STD heads ported by Dan Basiley of Baisley Hi-Performance in Portland OR.  You can by the heads from STD and have them port the also. Either way these heads will make more power then anything elce.  Johnny   602-705-7474