1976 Eldorado fuel tank vs 1976 Deville fuel tank. Differences?

[dennisspeaks]

For one of my other 78 Biarritz's I ordered a fuel tank from a 78 Deville but the tank arrived damaged and I sold the car.  Here I am again looking at replacing the fuel tank on my 76 Eldorado.  If memory serves me correct there is a few gallon difference?

Is the filler neck different?

[Phil Weber]

I'm not 100% sure but I think you are right. The only difference is the fuel filler neck . I've attached a couple of pictures of the 76 Deville and the Eldorado and they look the same except for the filler neck .
The carby and the EFI tank are different in that the EFi tank has a reservoir for the pick up . See picture.
You can run the carby tank ok just make sure to keep enough fuel in it . The fix for this is to run a Holley Fuel Mat attached to your pick up hose.

Phil

[dennisspeaks]

Thanks for pics and your reply Phil.  If old memory serves me correct the filler tube is several inches longer.  I have not been someone local to modify it and the solution is to cut and splice it with filler hose.  Yes I am aware the carb and EFI tanks are different.

I am just creating a back up plan as alternative to send it in to RENU for $1000 plus shipping.

[TJ Hopland]

I used a new reproduction made for EFI tank from another model GM car in my 73 Eldo.   May solve several problems in your case if the tank is in bad shape since it also included a more modern pump and sending unit.    Based on the pics the 73 and 76 look to be the same tank.   

The tank I used was from Tanks Inc and is the TM37C-T and was listed as fitting a 65-66 Biscayne, Impala, Bel Air.  I got it as a complete kit from Summit with the sender and pump/sender.  I think it was around $600.   The tank is about the same capacity as the original, 24 gallons.  Its shorter front to back and slightly wider than the stock one.   I don't have a stock resonator so I didn't have any issues getting the filler centered in the opening.  If you had the resonator you may have to shift it off to one side a bit which could require a little more creativity with the filler neck. 

Tank came with new straps that I was able to use with the existing rear strap mounting points.   Being shorter than the original I thought the best way to deal with that was to drill 2 new holes through the trunk.   There are a couple rails that extend out and had the factory speed nut things on them.   I made giant washers to straddle these rails so it wasn't just hanging on the thin trunk floor.  I also welded the bolts to these plates so I didn't need someone in the trunk holding a wrench on them when i installed the bolts.   There is a giant hump in the trunk and these bolts end up up against the hump so its not like there are 2 big bumps in an otherwise flat trunk. 

The filler neck on many of their EFI tanks including this one is just a nipple on the tank and then they supply a coupling hose and a neck.  I suspect this is because there were many GM tanks that were the same other than the neck so this allows them to have 1 tank that fits many different cars and years.   I would also guess it makes shipping a lot easier and less prone to damage.    To make mine fit I ordered a 30* universal hose they had which gave me more length to work with plus the angle I needed.   I ended up cutting that universal hose down a bit and cutting some off the metal neck piece so now its in the exact factory location.

My kit came with the GPA-4 pump and the standard 5 bolt float sender.   If I was to do it again I think I would get the GPA-2 on the hopes it was a little more quiet than the 4.   I would also try their 'float less' sender.   The float one was kinda a hassle to set up and isn't any more accurate than stock was.