After fiddling with the reducers so I could connect the aux tank to the pump, I found a better wat. I found 1/8NPT fittings in 5/16ths size for performance cars. Earls makes a 1/8NPT to 5/16 hose barb so that solved a LOT of problems. The only issue is the rubber fuel line can’t make the sharp bend to the barb on the tank without kinking. So I made an elbow out of 5/16ths tubing and used that as the radius. Now the fuel line is happy and so am I! A video too: https://www.youtube.com/watch?v=6-lRbVEu89k