They will run in the 9s.. the thing about
W-2s you need to watch for.. they made them
in 2 different installed heights..1.88 which
is the standard lenght valve and then they made
a 2.00 installed height which use a long valve..
I have a set of each.. on my Rampage I am running
the long valve W-2s which I ported and they flow
310 at .650 with a 2.08 valve.. they could go a
little more but core shift might be a issue.. mine
have some core shift and I busted through 1 intake
runner when I was clearancing the push rods.. I had
to tube it... I run 9.56 with them.. thats with the
same cam I have in the 416 right now(.640 lift)...
they are a very good head but heavy.. alum heads will
knock off 40# for the pair... this 416 dynoed at 590hp
with a 950 carb
EDIT
Also when I ran that 9.56 it was with a 395ci