Kevin,

I've got a few comments - a cross-flow water rad. on the cool side should work well.  Can you mount the oil cooler horizontally across the nose instead of vertically.  That would eliminate one inlet air turn prior to the radiator..  The muffler may not be required given the softer tone of the Renesis exhaust and the fact that you are planning a "log" collector on the exhaust already.  My intake on my flying Renesis powered RV-7A is not providing any added hp. I'd like to know how your intake works when you get it going.