Ok, I know that head porting should only be done by experienced professionals, etc, etc. I have a friend who has ported several sets of SBC and SBF heads with great levels of success. However, he has never ported a set of LS1 heads. My theory is this: The least expensive set of ported heads that I can find is ~$1500. I have read to expect gains of 30-40HP for a good head, and another 30 or so for a cam. I would think that you could gain "similar" amounts via a good valve job and some well placed cleanup and mild reshaping. Our question is this: I know that no "big name" head porter is going to give away their secrets, but can someone shed some light on what areas to concentrate on. The motor will probably recieve a 224/228 or so cam, and about 150 hp of NOS. I would assume that with the NOS, you would want to concentrate on the exhaust side of the cylinder heads. What about the combustion chamber and intake runners? I would assume a mild cleanup and polishing. I think that you could gain favorable amounts of HP and TQ per dollar spent going this route. Let me know what you think.

 

I am about half way finished porting my own heads. I don't have the money to buy pro ported heads and would rather take a stab at it for the experience. I am focusing on the seat and bowl areas, along with the valve seat angles. Read the book by David Vizard on how to mod chevy small block heads. Most of the principles apply. Its hard work. I'm glad I don't do it for a living.

 

Make the bowls .89 x the valve diameter. Be sure to radius the entry on both seats. Particularly the exhaust. Either eliminate the guide supports or taper so they are zero diameter at guide. Radius to relieve the combustion chambers at the valves so the diameter across is the same as the bore diameter. Grind inlet and outlet ports to equal area throughout.

This should give you the basics for a good street port.