Thanks for the tips, I'll move forward with no cylinder spacers.
The heads are stock 1.7 parts so I was basing my calculations off of a general cylinder head combustion chamber measurements for stock heads. Found a real handy calculator online where you can input in all of your numbers and solve for C/R.
The blueprint is 100% vector. This means I can scale it as big as I want and the lines will remain crisp. I'll be printing a few posters and selling them at the various events I got to over the year. I do need to make some edits beforehand though, as you noted the blue isn't quite right. Additionally I need to add a few center lines.