(quoted from post at 15:22:19 01/19/23) Be careful, the one in the link is 3/4 and you need 5/8. Below is a picture from
the Weatherhead catalog. You need 41157x10. Discount Hydraulic Hose carries
those but are out of stock, link below. Also note it adapts to 5/8 JIC which is
not a very popular size.
You could chase the threads with a bottoming tap made for 5/8 JIC or ORB meaning
7/8 diameter and 14 TPI, but not a regular coarse bolt tap because the pitch is
different.
Also in a later thread I posted a Weatherhead crimp-on fitting for 1/2 hose and
5/8 O-ring Port,no adapter needed. However it comes as a 45 deg bend model.
<IMG SRC =https://i.postimg.cc/jjx3wpnx/Weatherhead-Adapters.jpg>
Ford Adapter Discount Hydraulic Hose