Basically the older ones have more
meat to work with,when welding them
etc. They are put on a CNC
machine and does his magic.
A test was run on them in a controlled
environment ( Lake X ). It was on a
cat, Herring's skeg was 3 mph faster.
Apparently they kept swithing the old drives
and Herring's drive's back and forth
to make sure it wasn't a fluke. And every
time Herring's skeg was 3mph faster.
Just what I was told