I have seen some dyno sheets on this forum showing black cover 20 valves with about 86kW at the wheels compared to 76kW for the silver cover (close to a good 100 Kw 4age 16 valve motor).
Can any one vouch that the black cover 20 valve does put out more real world Hp than the silver cover (even though they are only suppose to be 3 kW apart)?