1974 Southwind cooling hose layout?

I'm transplanting a Chrysler 318 from my 1969 Barracuda to my "new" 1974 Southwind 18. Easy, right, since they were originally both 318 boats? Not so fast.

The Barracuda had two hull pickups, a dual pocket (2 intake, 2 exhaust ports) impeller pump, and a hose routing scheme that would make Rube Goldberg proud. The Southwind only has one hull pickup. The Southwind had no engine when I got it, and only some of the original cooling hoses present, so I don't have a good "go-by" there.

Obviously I don't want to starve my 318 for cooling water, but I don't even know whether the 1974 would've had a single or dual pocket impeller pump. I assume if it was single, then I can just use a Y- or T-fitting to split the incoming water from the lake. But, then, my 1969 had one hose running to the top of the thermostat housing from one side of a T-split coupler immediately after one of my hull pickups. I suppose that was to supply some water through the engine regardless of the thermostat opening. So how to replicate that and provide two intakes for the impeller pump? Two T-fittings? The single hose is smaller than the original two were, so will I be starving the engine?

I learned a couple of years ago that just because the exhaust manifolds have multiple possible intake ports for cooling water, you can't just hook up the water anywhere. Contrary to conventional wisdom and what simple observation might tell you, they REQUIRE an "optional" internal copper tube and connection at the lower rear to keep them full of cooling water. The system is a little more complex than first glance might tell you. So I'm a little reluctant to employ the "trial-and-error" method.

I wonder if anybody has diagrams anywhere of the Southwind cooling water system, or one similar to it, even if it's a different year? Or, better still, comprehensive pics of one in action?