Don't hook up the
oil cooler unless you track the car. With the size of the radiator the engine is already over cooled. If you do hook it up put in a thermostat bypass
Any reason you're rebuilding the engine instead of just getting a new one? You have no idea what can of worms is in there. It sounds like the car was rode hard and put up wet and a rebuild that will discover and repair all the abuse it's seen will be as much as a new short block. And you won't be revisiting it again in two years