Heater hose question

[astat1]

Can someone explain the purpose for each of the 2 heater hoses on a 1970 440 (no air). What flow pattern do each (larger and smaller diameter) take. While still dealing with my car running a little hot (195-215) I noticed a leak coming from the larger diameter hose on the firewall. I need to confirm the routing of each hose from the front of the engine to the firewall (larger and smaller diameter). I just noticed this and have not had a chance to check it out any further on a cool engine. A photo would be great. Thanks

[John_Kunkel]

The smaller hose is hot water from the engine to the heater core, the larger is return from the heater core to the engine.

The smaller hose attaches to the firewall nipple closest to the fender, the nipple closest to the center of the car is the larger return hose. They are routed along the inner fender panel with a support bracket about half way along.

[astat1]

Which hose is the return going to the water pump (front or rear) on a 440?  I have seen alot of engine compartments with hoses running from the water pump both ways.  Thanks