Truly correct replacement gas tanks

[Duodec]

Time for my once every few years query (first time on this forum).  Does anybody make a completely correct reproduction fuel tank for '71 Challenger that includes the internal expansion tank?

My tank was somewhat rusted, then the place I took it to to 'boil it out and clean it' punched a hole in it.  So far every repro tank I've found including the (still?) recommended Spectra tanks omit this exceedingly useful feature.  I've contacted two places that now sell a stainless steel tank, which would be a really nice thing to have, to ask if they do a fully correct reproduction but neither has responded (which I'll take as 'no expansion tank for you!').

So.. any correct tanks out there?  And if not, anyone tried one of the stainless steel tanks yet and can speak to their quality and fitment?

Thanks.

[anlauto]

Do you have a picture of the internal expansion tank ? I've never seen this before ? I thought the four vent lines were just tubes inside the fuel tank and the venting was done externally

[cuda hunter]

  

[JH27N0B]

I replaced the original gas tank in my '71 Challenger with a Spectra when it went bad on me.  I was very impressed with the Spectra when I compared it to the OEM tank, and didn't notice any differences?

[Mrbill426]

Like to see that myself.

Do you have a picture of the internal expansion tank ? I've never seen this before ? I thought the four vent lines were just tubes inside the fuel tank and the venting was done externally

[Mrbill426]

Put a Spectra in my '72; old and new were identical... except the new one wasn't rusty.

I replaced the original gas tank in my '71 Challenger with a Spectra when it went bad on me.  I was very impressed with the Spectra when I compared it to the OEM tank, and didn't notice any differences?

[cuda hunter]

I put a spectra in my early 70 bh barracuda.  Same exact tank. 

[torredcuda]

https://www.hamtramck-historical.com/ServiceHighlights/_1971PassengerCarHighlights-02.shtml?load_img=22

[torredcuda]

https://www.allpar.com/threads/fixing-1970s-and-1980s-fuel-evaporation-control-systems.229057/

[EV2RTSE]

I've always been under the impression too that there are no expansion tanks in any of the repops. I guess the big question is, how necessary are they?

I know on my brother's car he accidentally was running the wrong cap for a while. At one point gas shot out and ended up damaging a small area of paint below the gas cap. Would an expansion tank have prevented this? He's running a repop tank, I forget which brand but most likely a Spectra. Since that happened I'm considering reusing my original tank if it's savable.

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/665669/gas-tanks-all-the-same.html

I think the expansion tank was originally used regardless of ECS / non-ECS, etc.

[Floyd]

i'll have to dig it out for a photo but I'm pretty sure my original 71 tank has this small relief valve (circled in red).  I don't think the Spectra tanks have those.  One other minor difference with the Spectra tanks are the extremely sharp 90 degree corners on the tank.  The originals were rounded/had a radius.  An easy fix though.

[Skdmark]

i'll have to dig it out for a photo but I'm pretty sure my original 71 tank has this small relief valve (circled in red).  I don't think the Spectra tanks have those.  One other minor difference with the Spectra tanks are the extremely sharp 90 degree corners on the tank.  The originals were rounded/had a radius.  An easy fix though.

On both details.

[Duodec]

Thanks to those who posted.  The info is in the 1971 service manuals also.  Personally I think the expansion tanks _are_ useful because they would likely prevent a gas-spew out the filler or the vents if you completely fill the tank and it gets very hot.

Admittedly part of the point is it is 'correct' for a 1971 car, and the tanks available now are usable reproductions but are not correct.   I was hoping someone might have heard about a better repro becoming available.

[Duodec]

The four vent tubes do go to the top corners of the tank.  The expansion tank is attached to the top of the tank, in the middle.  It has a metered orifice in the bottom that can slow admit gas if pressure in the tank goes up (and the gas is up to the level of the bottom of the expansion tank), then meters back out as the gas level in the tank falls.  It also has a vent and rubber plug in the top of the tank visible from the outside.

There were previous discussions about this feature here on this board but from a couple years ago.

[cuda hunter]

I do recall those previous threads about this gas tank.
Sounds like the search function is your friend.  Please link us when you find the older tank thread with pictures.