5/8" heater hose and can only find 1/2" fitting

go midhose. I think most parts stores and even lowes would have a fitting that lets you run one size hose to this fitting then run the other size hose from there to the ending point. Don't have to make everything fit at ends-heater core and intake. I think my Durango came stock with this adapter pice in the middle of the hose sections.