i run the same engine on my bernico 19S.
the engine is bleuprinted and tuned,with altered cilinderheads (26cc) to run on regular gas instead of racing fuel.
rev limit is 8500rpm and it still delivers 280+ hp.
with the racing fuel cillinderheads it needs rebuilding after 15-20 hours.
only the hours above 6000rpm count for rebuilding !! so ive been told by one of the finest tuners of merc engine's in belgium.
i havent got a gps reading yet but the speed should around 80-85mph with a 19pitch 4 blade mercury offshore (vensura) prop
btw!! if anyone knows who selling this engine?
ive maild to the person 4 days ago and havent got any answer yet