Because I have STRIKER heads not ported stock castings
Because the Striker heads are totally different head castings. Not a gen2 stock casting that starts out flowing 220 cfm then get ported, they flow 330 cfm the way you take them out of the box. And there is more to it then flow numbers too, they are just flat a better designed head.
Yes you can make very good power with the stock castings by porting them (I have picked up 70 cfm in the intake side by porting Gen 2 castings even using the stock valves), but you can make more with the Strikers. You will pay more, quite a bit more in fact for a Striker head set-up then you will for any ported stock casting Gen2 head but you will also get more. Just depends on what you are looking for is it worth it to you to sped the extra $$$ for the extra 20-30hp you will get with strikers with all other things being the same?
Now starting with Gen3 heads is a different story, you can get ported gen 3 heads to flow as well as the striker street heads do.
