I purchased the Spectra Premium GM34C fuel tank, and the Spectra Premium FG91A Fuel Sending Unit which has the 3/8” tube for the fuel hose to attach to. Also, from Inline Tube, I purchase the INL12273 Fuel Tank Vent Tube Set, and the FHS301 Rubber Fuel Line Set (3/8” hose with four correct green pinch clips). The two vent tubes fit snugly by working them onto the gas tank vent tubes and secured with a black pinch clip for the 1/2” hose, and a red pinch clip for the 1/4” hose. However, the 3/8” rubber fuel line slid easily onto the fuel sending unit tube without any effort which I then secured with a green pinch clip. Should the 3/8” rubber fuel line slide on easily? Maybe I am overthinking this, but I was thinking I would have to work it a little bit to get it onto the sending unit tube. I went to the local O’Reilly’s Auto Parts tonight I picked up a 5/16” Gates rubber fuel line hose and it wouldn’t go onto the fuel sending unit tube. If I put some lubricant onto the tube I could probably force it on. Let me know your thoughts if anyone has purchased and used these products, since I don't want to have any leaking fuel.

 

Are you working on the Cutlass in your picture? I have coaxed on a little too small tube on a fitting using some wd-40 as you said and it seemed to be OK. I wouldn't use regular oil on it cuz it may cause the rubber to swell..? But I'm sure using too large rubber tubing onto a steel tube isn't good. I bought a fuel tank sending unit thru Rock Auto for my 71 Cutlass and it had the correct size fittings- the same as the original one did.

 

Thanks for the input Greg. And yes, it is the Cutlass that I was putting in the new tank, fuel sending unit, hoses, etc., and I was able to get an answer to my question. I contacted Spectra and told them my issue, and their technical support person said that the size of the fuel line hose I should use with their FG91A Fuel Sending Unit is a 5/16” hose. Seems odd that on the website it states a 3/8” outlet. I would have thought you would use a 3/8” fuel line hose with a 3/8” outlet, and not a 5/16” fuel line hose, but I guess not.

 

They probably had a manufacturing screw up, 3/8 would be the proper size