I am looking for the manifold that is made by Volvo with separate
chambers for each cylinder which run all the way down the throat of
the manifold. It is galvanized and sells new for $700, that is why I
am looking
for a used one. The new manifolds from Osco sell for only $230, but
don't have the separate chambers.

I'll be putting the good manifold on my 198719 ft Bayliner that has
an AQ131A four banger, gas efficient, yellowtail killing machine.

I am rebuilding it because the original manifold with the single
chamber caused water to be sucked into the rear piston and caused a
valve to crack. Luckily I shut her down immediately when I heard the
wicked noise she made and the cylinder was not damaged. I am
replacing the head and a piston and putting in new rings.

I understand that Volvo made this separate chambered manifold because
the aforementioned problem was occuring on many of the AQ engines.