I am basically fully rebuilding my motor and ordered a cometic top end gasket kit as part of the required components. What i have noticed is that the head gasket is only .25mm thick, the gasket which it is replacing is 1.1mm thick which from reciepts of the previous owner is a kwakka original. This change in thickness i have calculated at a 4cc reduction in combustion chamber volume. I have yet to assemble the bottom end to to dummy assemble the top end to check my squish clearances. Could someone in the know please advise of: what head gasket thickness they run when using a std cylinder (deck heights std), what would be a good/reliable combustion chamber volume (measured with tranny fluid in burett dropped into plug hole at tdc untill level withtop), what is optimum squish clearance and if not too much to ask the port timings that people set their barrel height at for both an unported barrel and a fully modified one. (this may be too much to ask)
Also the premium unleaded petrol from a bowser in australia is 98 octane i believe and i am unwilling to pay twice the price for some doubly expensive imported high octane fuel.