Does anyone know what the inside diameter (ID) of the OEM FD heater hose is, or the outside diameter (OD) is of the hard line piping/nipples? Would like to find out without opening up my cooling system

Anyway, my FD is lacking the hard pipe section due to the PO's single turbo installation, and the run is currently all hose. I'm looking to make a custom AL hard pipe section to get around the hot turbo area, as I don't like the idea of a rubber hose being exposed to so much heat.

 

Hard pipe OD: ~ 0.67-0.68" or ~ 17mm

largest diameter around ridge is:
~ 0.73-0.75" or ~18.7 mm

 

Thank you Sir!