77 280 "hard" water line

I need the hard water (coolant) line that runs along the front of the valve cover. It is the line that supplies coolant to the block under the air regulator on top of the intake manifold. Mine has a pin hole and I can't locate where exactly. It is corroded and I'm not sure it is worth fixing. So I'm hoping to find someone with a parts car or such that can sell me one that is in great shape. Please let me know. Thanks.

Bob