[chas350]

x2 on the brake fluid flush.
I would also consider the water pump.
What about gaskets and seals? As you probably know, the 2 piece rear main seal on a small block Chevy is not a good design and is pron to leaking. The valve cover, oil pan and intake are also leak spots. Gasket makers have muck better products avail now compared to the multi-piece cork junk used by the OEM.