She,s a beauty mate nice one ! Is that an Austrialian cloud or UK one haha . The general way of thinking (not always) with a road engine is keeping the comp ratio standard or near it at 8:1. There are known engines that are above that level of compression for reasons i dont know really but response/driveability and off bosst performance can be improved by raising the ratio for instance. There must be lots of factors that determine it and when maybe good time to do this . Budget may also be a factor and ultimately what your after exactly. Big boost and high compression is definately doable with huge figures i think Rods YB is 8.5:1 massive boost but it isnt exactly your average road engine/car although can be used this way still .