I am in the very early stages of restoring my 1968. I went to repalce the fuel tank and pickup. When I bought the new tank and pickup it only has an option for a pickup with 1 line. My old one has 2 lines. Does anyone know if the second line is a vent? There are 3 lines to the fuel pump. THanks!
Yes, the smaller line is for your vent from fuel pump. It goes along driver's side of body. You will need a sending unit for two lines, they are available at most of the restoration parts places, I suggest Firebird Central. I just did mine this past summer, but single for my car.
Thank you my friend! I will take a look! NPD only had a 2 line pickup for a 6 cylinder. I assume that will not work. The only pickup they had listed was a one line. Strange. Thanks!
Not a vent, the only vent in the system is in the gas cap on first gens. It is a return line to the fuel tank keeping the fuel constantly circulating from tank to pump and back in a loop. this has two main benefits, first keeps the pump and fuel from being deadheaded, secondly and most importantly it keeps the fuel cooler because it's always circulating back to the cool sump of the gas tank. Very important with today's alcohol fuels and there lower vaporizing points and vapor locking problems. All 400s and also all 350 400 with a/c cars were originally equipped this way because of their higher under hood temps. Ames performance engineering should have everything you need.
I got mine from Classic Ind. It you search the OER part number, you might find it cheaper or with a place close to you, so you can pick it up and not pay shipping charges.
It has always been my understanding and direct experience with the original cars I have been exposed to over the years that all 400 cars and also a/c cars used the vapor return line because of the higher under hood temps associated with them. The Pontiac/GM parts book supports this as they list the 350 2bbl non a/c gauge assembly/fuel sending unit without return line different from the 350 a/c unit with return line which carries the same part number 6427857 as the unit listed for all 400 engines. Ames and some of the better parts suppliers also list it this way. I am in no way saying you are wrong and if you know the sending unit and fuel pump have never been changed since your car came from the factory then I guess there's the proof in your car. I am only interested in spreading as much correct information about our cars as I can to help first gen lovers but have also learned to never say never.
Want to fix my wording on this to not mislead anyone in the future. When I said the only vent in first gens is in the gas cap, I was forgetting about the early 69's which had a vent tube in the filler neck on factory tanks and used a non-vented cap. Of course, this was changed during the production year and eliminated. Also, the cap was changed back to the 67,68 vented style.
No problem, it appeared to be original tank, still had original hose & hose clamps on filler tube and just seemed to be original. My car has a strange history...