A flat top piston in a 292 will put you real close to 12-1 compression. If you check out the dyno test we are currently doing on a 292, you can pick up some useful info for your project. This engine has a 27cc dish forged piston, and with the 70cc chamber head gives you 8.8-1 compression. So you should be able to get close to your goal of 9.5 with some head milling, depending on which head you have. We've tested this engine with the Clifford and Offy intakes, and several different cam and head combos, so theres a lot of helpful tips there.
