Edelbrock LD340 WTH?!?!?

The switching around of the runners from lower to upper plane could be due to a couple of reasons that I can think of; one is just packaging. If you look at other brand engines that have the same firing order, they vary in which cyls are upper & which are lower plane. Does it really matter? Somebody at Edel finally woke up [ maybe somebody went to Germany or Japan to see why they there making big HP #s ] that big runners are not as effective as smaller runners, hence the smaller CSA of the Perf intake. The new Perf might have been easier to package with the planes reversed.
The other possibility I can see for switching the planes. #7 fires after #5 cyl, so # 7 can get robbed of incoming charge. Short on air. Moving #7 to the lower plenum which has greater volume, might help with providing more air to #7.