would i see any real benefit swapping out a set of well ported ls1 heads(300cfm at .600) for a different set of ported aftermarket heads?

another way of saying it would be; what kind of results would an extra 10cfm of flow from .450 to .600 imrove power?

 

Not a huge difference. Might be able to pick up an extra 20 rwhp if you have a large port volume and the better flowing aftermarket is a smaller runner volume. The extra velocity and better low lift number could give an ok gain. I guess it depends on what you have now and what your looking at swapping to.

 

I think a smaller volume yet higher flowing runner might bolster low end torque, but I think seeing 20 RWHP from a 10CFM gain is really reaching, especially since runner columes affect the low end more than the high end.

 

Well I saw a head comparison that richard at wcch did with his heads. A customer that was running his old ls1 5.7 stage two heads swapped out to his new edelbrock cnc design with a 212cc runner compared to a 230cc runner and made an extra 20-25 rwhp. Also picked up some good power under the curve. Like I said before though. It all depends on what he has now and what he is planning to swap to.

 

as a general rule if you increase your flow by 4 CFM you will gain 1 HP