they have taken it down. Basically what he was explaining is as follows.
The engines come with .3mm head clearance already built into it without shims. so if we add .3mm of shims we now have .6mm head gap. So basically the engines come with I believe a shim stack of .5mm+the .2mm breakin shim for a total head clearance of .10mm that includes the .3mm already built in, that head clearance will cause the engine to run cool/pipe hot. so after break in we remove the .2mm shim bringing the total head clearance to .8mm. you following me? So after my engines are broke in I run a shim stack of .3mm-.4mm then you add the .3mm and you end up with .6mm-.7mm total head clearance.