While not unheard of alphas are not commonly found on 454's. They don't
hold up to big block torque well on a big boat. But with twins the stress
would be less so maybe. If they are alphas then it's either the rubber hub
in the prop or the rubber coupling hub on the engine flywheel. Everything
inside alphas is metal to metal, no clutches. Hope for the prop hub cause
usually the engine has to be pulled to replace the coupling hub on the
flywheel.

"RM" wrote in message
...

"JamesgangNC" wrote in message
link.net...
Depending on your drive system there can be clutches involved. Just
about
all inboard + lots of i/o drives except for merc alphas have some sort of
clutch system to engage forward and reverse. There are also rubber
couplings that can exhibit the same behavior when they have slipped.
What
is between your 454's and the props?

I think they are alphas, I will go to the marina in a couple of days and
check.