On the Shipman page , the cutaway diagram of the Hex jet and Round head shows the Round head internals to be identical
whichever way the fuel flowed . The Hex jet wasn't , so flow differences in flow direction makes sense , in that instance .
Mark and I are pretty much the same Vintage , so I fully expected he'd have had a copy of Carl's book .
There's a lot of good information in these old books . still relevant today . The Laws of Physics all still apply .