Vip
The heads are the best place to start. Stock heads can be ported to gain an HONEST 25-30 HP with a good valve job. It is a job for a professional or someone very experienced with a die grinder(a Dremel tool WILL NOT get the job done). A good set of heads with a weak cam will outperform a hot cam with weak heads every day. It depends on your budget & goals between iron or aluminum. I just did a set of GT40 heads picked up 21cfm on intake, 12cfm on exhaust! I am in No. VA if you are interested.
Greg Parker
Steadfast Performance
Cylinder Head Porting
Flow Bench Testing
703.609.1200
www.steadfastperformance.com