I did this about 15 years ago on a GM single point injection throttle body, the faces aroung the port were flat so used a copper washer.Somewhere like think automotive could get you an adaptor from that to a barb.
Classic Saab 900.What car? You can probably get a 2nd hand rack cheaper than the tooling to make it yourself.
Not found anyone locally yet able to make in same ballpark as per originalcall in a freindly hyd hose workshop......they have all kinds of weired stuff......




