Back in 05 I was at the Turkey Rod Run in Daytona. while looking for odds and ends item for my 72 I found a NOS looking overflow tank. Same one that came on my 72 but wasn't yellowed. So I bought it. Put it on durning a engine change from a 402 to a 454. As always there a some lose ends to fix which do to travel for work dragged out over the summer of 08. First few times a drove it I notied that the radiator hose was sucked in on itself when it cooled, but looked fine when running. Shortly there after noticed a small leak from the side tank on the raditor. Changed the radiator to an aluminum and still noticed the hose going flat when cool. Changed the radiator cap and checked the hose going to the overflow tank. It was still doing it. So I decided to take the take off losened the hose to hear a gasp. Turns out the plastic nipple on the tank had no hole through it. Drilled out the nipple and now the radiator hose keeps it's form, fluid actually moves from the radiator to the tank and back. All said, simple problem ate a radiator in the process for finding it.