standard valves are plenty big enough for most anyways
agree but they don't flow alot for the size...it's due to the shape of the throat/height of the roof.
With the head completely standard and lifting the valves to HKS 264 specs (in-11.35mm. ex-10.85), the inlet flowed 130cfm, the exhaust was 66% of the inlet (or 86cfm), low lift flow was ok.
flow is now up to 101cfm, that's about the same as a Cossie with virtually no work.
It's just something i want to try on a scrap head before fitting it to my good one.