Last year I had to replace all the rubber pieces on the carbs of my 4th Gen. Had no problem getting the Orings and gaskets from Partzilla, but the two fuel lines that connect the front carbs and back carbs were discontinued. I ended up using fuel line from the auto store and while it was a tight fit I made it work. Fast forward to this year and the fuel line was leaking again. The main problem is that the fuel line is bigger than stock and less flexible while also needing to bend at 90 degrees to fit together at a 'T".
While looking for better quality replacement fuel line I decided to look at other Honda models and discovered that the parts from a 97 - 03 VF750C Magna looked similar. Looking at the carb assemblies of both models I found a lot of the same parts. Like the main bracket that connects the front carbs to the back carbs. Also the 'T' joints that provide fuel to the carbs. I took a chance and ordered parts
16197-MZ5-670 and 16198-MZ5-671 -> 97 - 03 VF750C
instead of parts
16197-MZ7-640 and 16198-MZ7-640 -> 94 - 97 VFR750F And the Magna parts fit perfect. So far no leaks, but the real test will be how well they perform next year and the next 16 years like the originals.