No John and Tony, I wasn't asking if there was some super duper widget. If there was, it would only be available in Japan anyway...
I was curious if there was any special prep work or machining, like rocker profiling or lightening, some nutty valvespring design, etc -that sort of thing. Something beyond what all the Datsun books originally written in the 70's detail for race engine prep. 20-30 years is an eternity in the racing world.