[Guest]

USAAF tests on the subject said that both late and early versions were too close to make a big deal over. I don't consider "official" USAAF records to be totally accurate. That IVa info was gathered from field info. I still can't find the link, but it's out there somewhere. They had a tendancy to underate planes. The difference will be small, but it's for historical purposes and be assured it will be accurate.