anyone care to explain rear water outlets or tell me a link to where i can learn about em? I bought the edelbrock 7501 intake and it has rear water outlets. Ive seen pics that show steel braided lines connecting both water outlets on the manifold but ive also seen the lines connected to an adapter beneath the water neck. Whats the difference between the 2?

if you connect the two rear it becomes a coolant crossover or you could attach one side too your heater core.

when you say connect the 2 rear do you mean connect the 2 rear to the 2 front and that is the crossover or connect the 2 rear to eachother to make the crossover?

There's various ways to do it, the theory being that it can keep temperatures more consistent throughout the heads. Not worth the effort on most engines.