kx3g

Can anyone tell me if the 6 cyl gas tank is the same as an 8 cyl tank. My 350 tpi tank is leaking and I want to replace it with a factory tank. Hoping to have more availability if it will.

Tks

mantaguy

iTrader: (5)

According to the parts book 89 used different tanks for the 6 and 8 cylinder cars.
6cylinder used P/N 12509205 and the 8 cylinder used P/N 12509285,I don't know what the difference is.But here's were It gets confusing, for 85-87 they used the 1 tank for both 6cyl.and 8cyl.(LB8,LB9) P/N 12509205 witch is for the 6 cylinder in 89.Same thing for 82-86 They also used the 6cyl.tank

nhra-trans-am

iTrader: (7)

I had a similar problem with my tank leaking from the filler neck on my 89 TTA. I ended up replacing it with one from my 91 Firebird (previously 3.1L V6). Didn't notice a difference and the gauge still reads correctly in the 89.

mantaguy

iTrader: (5)

The 91 V6 used the same tank as the V8 and the 89 TTA used the V6 tank, So I would imagine that they'll all fit each other. Their is no explanation why these tanks have different P/Ns.

RubberDucky

iTrader: (4)

You pretty much have it. I've pulled tanks out of V8 cars, and out of my V6 car. They are all the same. The only one that's different is the 1LE tank.

kx3g

Thanks for the info. I'm trying to find a '91 or '92 tank for the baffles. Sounds like I can use a 6 cyl. Been looking for a while so maybe adding the 6 cyl tank to the search will make one easier to find.

Tks

a62belair

What about a plastic 4th gen tank? Don't they fit, too? I was contemplating a swap to one for my Formy...

kx3g

I've read that a 4th gen tank will work, but you have to get a new sending unit.

nhra-trans-am

iTrader: (7)

The 4th gen plastic tank does fit. That is what I put in my 91. Also did the sending unit swap so the gauge still reads correctly

kx3g

Nhra, Is there a DIY or a write up on the swap somewhere? I've done some searching and found that the tank fits fine, the issue appears to be ohm related in the sending unit. I haven't found the solution to the sending unit issue yet. There was also some question about a canister that's on the plastic tank that isn't on the 3rd gen tank.

Any additional info you can provide will be much appreciated.

Tks

nhra-trans-am

iTrader: (7)

Not sure if there is an official write up, but I just went off what I found on this site through search. The tank is a direct fit, the only thing that had to be modified, was the filler neck since it is a little long. It just needs to be trimmed down.
As for the sending unit I used a unit from a grand prix I believe, which is the same style/connector plug as the 4th gen fuel pump/wiring, but has the correct ohm resistance as the 3rd gen gauge.

kx3g

Thanks nhra. Do you remember about what year Grand Prix?

nhra-trans-am

iTrader: (7)

GM part number #25319676 - sender out of a '97 Grand Prix

kx3g

Thanks nhra!