I would pay up to $ 1,000.00 for a running 10 HP especially if it comes with
the var. pitch prop and shaft.

It *HAS* to come with the variable pitch prop and shaft. That is the ONLY
transmission made for the engine.

Those old engines have great torque at low rpm

HP = torque times rpm. If it has just 10 hp and it achieves this hp at lower
rpm it MUST have higher torque (otherwise it wouldn't make 10 hp), and this
means it MUST have more cubic inch displacement. There is zero point zero
advantage to "more torque". It is the hp you need to drive the boat. A 90,000
rpm turbine engine, or 12,000 rpm racing 2-cycle, or 9,500 rpm racing 4-cycle,
or a 6,000 production 2-cycle, or 4,500 production 4-cycle, or a 3,000
production diesel, or a 1,500 rpm industrial diesel, or a 500 rpm mule diesel
engine, or a 50 rpm steam engine, or 10 plough horses (actually, about 8 plough
horses as Jimmy Watt kinds fibbed a bit about the strength of plough horses to
help sell his steam engines), are ALL just 10 horsepower, and it *IS* the hp
that drives the boat.

but still, I
would prefer to see a 20 in there.

The 20 hp Sabb engine weights in at 880#, or well more than a 750 hp MoPar
hemi.

You REALLY have to like the _thought_ of a seriously heavy, low output *diesel*
engine to think that the Sabb engines are anything useful.

Think of it: a 880# engine that puts out less hp than a teenage boy's 180 cc
motorcycle.

Again: it's a great engine.

As is a 2,000# 2hp steam engine in the right circumstance, but it gotta be a
character type boat to be the right circumstance.

A huge displacement, high torque, slow turning 10 hp motor puts out no more hp
than a tiny displacement, high reving, low torque 10 hp motor.