Quote: Sorry, I would have to disagree about the W9's being the same as the GM SB2 heads. A well flowed CFE W8 head is around 420 @ 0.9 lift where a SB2.2 head @0.9 lift has been around 450.
Not my statement but a repeat of what an engine builder that has worked with both heads told me.
These were W9-RPs and SB2s. He said he used they same program on his CNC to port both.
