In advance of me getting there on my build just to make sure I'm getting it right in my head....For a holidaying me and Mrs Deefer bus with no racing intentions... Ditching the cylinder to head shims and going straight metal to metal there.. (with a light fine valve paste to clean up the sealing face?) no other goo. .. If chambers confirm to 55cc and piston dishes to 5cc.... I'm assuming I'll shim (no other gaskets just sealant?) at the base of cylinders to get a deck height of about 1.5mm giving a CR of 8 : 1.. are these good target figures to work to given that the steps of 0.25mm in available shims will give a + - 0.2 change to the CR.