your builder should know what domes to run with his porting that will get certain compressions. in all my experiences 21cc domes will get you right around 170 psi, 20cc about 175 psi and 19cc about 180 psi.. but thats me on my setups. i can tell you one thing though, 205 is too much and its recipe for disaster. youre putting a lot of stress on your crank and pistons running that much compression.