Hi John:
CIS offers VERY limited abilities to alter CO beyond idle, but I'd shoot for 2.5% CO using headers and low restriction mufflers. Without question, you should check your AFR's on a chassis dyno to make sure you are not too lean above 5000 at WOT.
Assuming that you are using 93 octane pump gas, stick with stock advance numbers so you do not inadvertently buy new P/C's,...
