What hose is used for the coolant tank overflow bottle to radiator on mid to late 70`s mopars? I bought a B0056 hose from Classic Industries and it is too large. The listing says otherwise. It seems to be a special hose that is more thin wall and ribbed. Anyone know where I can find one?

i believe it's 1/4" inside diameter, outside diameter close to [if not actually] 5/16".
it actually has to be a vacuum type hose, because when the radiator cools down, the fluid is sucked from the overflow tank back to the radiator. that is why these cars require a cap with two seals. one for the top of the neck, the other to seal against the necks bottom at the top of the tank.
parts store may have this on a bulk roll. if they don't, i may have a piece in my stash that will work for you. gratis.

Thanks, MoparX, The one Classic sent me was 3/8 ID. I know I bought one some years ago but I don`t remember where. I guess I should take the old one off and measure to make sure. I thought maybe someone would have a part number I could order off the top of their head.

5/16 overflow hose fit perfectly.

thanks