Merc did make some 8-port heads for the chevy ll four banger marine version, but as far as I can remember the sixes always were stuck with the stock 9 port (6-exh/3-int) configuration.
They were some 292s with Q-Jet intakes, but those intakes were made to deal with the water-cooled(or heated) exhaust manifolds.
I've wondered how they got 200hp from a 292 with just a 4bbl and cam.
If the head is stock(and the exhaust doesn't look like it is helping anything either) then I'm skeptical. You'd think it would take headers to get 200hp.
