I have a recently rebuilt 1600 crossflow with twin 40's port and polished head etc, im wanting to raise the compression in it as it is running standard pistons. Since ive just rebuilt it i want to just deck the block but what compression ratio can i go to with new zealand fuel? is 10,5:1 safe. im also going to change over to kent 244 cam as i have BCF2 in it at the moment.