Heater Hose Size at Heater Box?

[PeterVarga]

Dumb question here but here goes. What is the ID of the hose that inputs the heater core box? I have a garden hose that will flush it out but need to make an adapter. Dont want to pull it apart and measure it yet. Anybode know if it is typical 5/8" stuff? This is on an '02 of course.

[BillWilliams]

(nt)

[PeterVarga]

working on a '76.

[RandyMolson]

realoem says the late box connections are 18mm

[PeterVarga]

Thanks....I hope the hardware store has it. Some moron

wadded a square of barrier tape and put it in the heater

box....as a joke. And I gotta fish it out.