I have some flow data for absolute out of the box, AND as a footnote, in reality, even a "stock" valve job is 3 angle. We did a little bit of R&D development on these Chinese versions for another shop, and they DO respond to quality machine work, we came up with some low lift valve jobs for restricted valve lift oval track stuff, as well as normal street performance stuff. The castings are not terrible after working over a bit. I allways put bronze guide liners in also, I never run the iron guides as shipped