I would not be a bit surprised if you set the piston down in the hole to get the compression down to 9.5:1 it would have more detonation issues that at 10.6:1 with a nice tight quench.
Danm right build it right. He's such a domes days sayer. What if's abound in daily life and he's worried about jetting issues. Funny, I never ever did or had a problem. Cloged fuel filter? Don't you change them out? Regular service! Lean tune? Come on now. Learn. better yet, purchase a lil'known device called a 02 sensor and learn from that. It's actually amazing how lean a engine can be and still run.
Your acting like a worry wart over this.
The low comp. ratio pinging issue is so soooo soooooooooo true. My 400 is in that boat now. What a pig of a smog engine it is.