IMHO heads get ignored often because it isn't a bolt in solution but next to air cleaners and pipes they can deliver the most noticeable increase in power.

Heads are cc'd, dynaflowed, and ported and can also have tweaks done to the valve seats (tri-angle seat, for example). They can also have higher volume valves installed which increases flow. As long as you are adding air, you have to get rid of the air also. And with more air you have to have more fuel.

CC'ing the heads makes sure that they hold the same volume of gasses (balances the engine pulsing). Dynaflowing the head makes sure that the path of the gasses is the most efficient. Actually, IMHO hydraflowing is the best (a Smokey Yunick invention) because gasses flow more like water than like smoke. Anyway, you can look at water flowing in a stream and how smoothly the water passes through sections of the stream, how it speeds up in narrow areas, slows down in wide areas, and curls back on itself over interruptions will give you an idea of what this is about. Porting means that the mating surfaces have the exhaust and intake ports exactly matched and shaped to support the dynaflow paths.

 

Decided I'm just going to do a cam swap & dyno tune for now. If I still want more performance then I'll upgrade to a 103 or 107 with some head work. Cams I'm considering are SE204, T-Man 555 Torqsters & Andrews 48H.