radiator overflow

You'll need to go 73 on up cause there was none yet for an A-body in 71. You'll also notice the drain tube shoots off to the left side on your radiator, you'll have to make the hose do a u-turn because factory mounted on the right side. Almost everyone I get is cracked so I got nothing for you used.

You can also get a universal from the local parts store, you can pretty much mount it were you have room. They range from about $12 on up and they even make them in billet.