'Nother Cylinder head question

["Henry Bahn" <hbahn@home.com>]

It has been said that the cast iron head can produce as much as 6+ hp more
than an aluminum head in a modified R 16 race motor.  One possible reason is
better heat distribution . . .
But there must be other reasons for such a difference.  I've had several
people say the changing heads (same specs, al. and CI) on the same engine
show significant differences on the dyno.
Bill Wessel - are you out there?  Did Col. Joe ever experiment with heads?
JH Bahn

PS - My spell checker always wants to change "Wessel" to "Weasel" . . .