Remember that until recently, almost all KRs were built and flown with header tanks. I have never seen an appreciable change in CG either, but also have a 12 gallon header tank. However, when carrying a lot of baggage in the right seat, in my first KR, I could definitely tell the difference on flare after a long trip when the fuel was low. That does not happen on this KR, because I have the WB set farther forward. I believe that it does make a difference, but also believe that the amount of fuel and CG, determine whether or not it is a problem.
See N64KR at http://KRBuilder.org - Then click on the pics See you at the 2011 - KR Gathering in Mt. Vernon, Il - MVN There is a time for building and it never seems to end. Daniel R. Heath - Lexington, SC -----Original Message----- Don't sweat it. I have the 12 gal header tank