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This is my first post. I can't be the first one to think of this, so I thought I'd see if there's anyone out there that has had success or ran into any issues.

I'm restoring the undercarriage of my 72 Malibu coupe, and I ruined the original fuel tank by painting it with Eastwood's Tank Tone Metallic Coating (item# 10030 Z). I began researching fuel tanks, and found that Chevy offered a 20-gallon tank in 1970 only.

My original tank is a 17-gallon with three vents toward the front. I have a charcoal canister under the hood and no other emissions control.

Will the 1970 20-Gallon tank be a direct replacement for the 72 (17-gallon) tank. I don't see any other larger straps out there either. Will my original straps work with the larger fuel tank? (I assume that is what the really long front strap bolts might be for.)

The 20-Gallon tank that I'm currently looking at is on OPGI.com:
Original Parts Group - Part ID: AD0GM5C

It looks like a great buy, but if I order the 20-gallon and it doesn't work, I essentially will be eating it with the oversize delivery charges.

Thanks, guys!
 

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Hi David.

First off, how did you "ruin" your tank by simply painting it? The tank tone stuff is for external use, so unless you poured it inside, just strip it off??

I think the confusion comes from the emissions. I always get into "heated debates" about vented vs. non-vented, vs. tank size etc.

You actually should have a 20 gallon tank. It only has a 17 gallon capacity. The reason is GM had to have "dead space" inside the tank so they extended the filler neck waaay inside so it would "appear" full to you, the user, and the gas pump. The "wasted" space at the top of the tank is used as a vapor area so vapor can flow out the rear 3 nipples into the vapor separator and eventually into the charcoal canister.

Are you planning on doing away with all the evaporative emissions stuff?

You could just buy a standard 1970 tank, add a vented fuel cap and do away with the vapor/evap stuff.

Unless someone chimes in, I don't see how more than one physical size tank was used between 1970 and 1972. A tank is a tank as far as EXTERNAL dimensions go....
 

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I have a 69 Malibu and a 70 SS and have had a 71 Malibu, they all had 20 gallon tanks. Are you sure you have a 17?
 

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1971 Chevrolet Chevelle Malibu
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I just bought a 70 tank from RockAuto for my 71 Malibu. I wanted to eliminate the 3 vent pipes thats why I went with the 70 one plus the evap canister on my car is long gone anyway. Just have to run a vented cap now. RockAuto has some of the best prices on tanks and they do their best to protect it when they ship it to you. I see OPGI has a sale now check the shipping on both places also.
 

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Is the tank different from 68-72 or is the sending unit and gas cap the only difference??? thanks Rob

Rob,

The tanks are different.

1968 has a hard line vent tube coming out of (I believe, I'll let the '68 people chime-in).

1969 may have a vent tube as well, not sure.

1970 here's where the fun starts.

1970 vehicles NOT originally sold in California got vented gas caps and a standard tank.

1970 vehicles ORIGINALLY SOLD in California got EEC (Evaporative Emission Control). This is a special tank with 3 nipples opposed of the filler neck. These nipples connect to a vapor separator behind the rear seat. There is a charcoal canister under the hood that connects this. They used a NON vented gas cap. Filler neck extends way into tank to rob you of tank capacity.

1971 and 1972 Due to Emissions mandates, they follow the same style of California tanks in 1970.
 

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Don't know if they are the same for 68-72 but there are a number of different sending units to fit the tank depending on fuel line size, if it has a return line. My old tank had a new double line sending unit a 1/4" return line and a 3/8" feed line. I'm just going to cap the 1/4" line and will be running a 3/8" feed line up to the front with a vented cap.
 

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Hank,

Glad you brought that up. Yes, Senders are different.

AND, installing and utilizing a factory return line on my '70 is the best thing I ever did. No more fuel percolation after shut-down, so no more carb flooding, no risk of vapor lock, etc.
 

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When I brought my new tank down out of the attic, I found that they had sent me one with three vents on top rather than a 70 tank that has no vents.
Since I had bought it several years ago, I figured it was too late to send it back.

I capped off the three vents, then found out a 70 vented cap will not fit it so I bought two caps, a 70 vented cap and a 71 cap and made my own vented cap to fit the 71 tank neck.

As far as I know, 70 is the only year that had no tank vent tubes and used a vented cap.
68 and 69 gas tanks are the same with two vent tubes on the top at the passenger's side corner.
 

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Discussion Starter #10
Thanks everyone. I'm learning as I go, and I have a lot to learn! Looks like I'll strip the original tank... I just hate that I sprayed it with the Eastwood tank tone. It looks horrible, and I do not recommend it myself.

I could possibly be moving to California soon. Does anyone know if they do a visual inspection for the evaporator canister in that state?
 

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By the way, I have a 72 Malibu and have hot start problems with vapor lock or fuel vaporization. I'm strongly considering putting back in the fuel return line that had been previously eliminated by a prior owner. That will of course require a change out of the current fuel pump too.

From what I've read, this will go a long way toward eliminating a potential vapor lock on hot summer days.
 

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Sorry to dig up an old thread. But can’t find the info I need any where.
Will a 70-72 fuel tank fit under a 68 chevelle. I’m in Australia and need a new tank and can only find 70 or 71-72 tanks. The vent differences don’t bother me as I’m modifying the tank to take an MRA style drop in fuel pump.

Thank you heaps for any information.
 

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Sorry should of been more specific. I can’t find a tank here in Australia.i would buy one from the states but shipping is around $1000.
 

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Sorry should of been more specific. I can’t find a tank here in Australia.i would buy one from the states but shipping is around $1000.
I may have made a mistake but I just 'estimated shipping' on the Spectra tank from Summit and the cheapest was about $185 US shipping, $34 US tax/duty. Plus the price of the part.

If that's in your price range, you may wish to check it for REAL. It also appears to be back ordered until Sep.

Pete
 

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Can someone explain what the 1/4" line is for that is attached to the long 2 line fuel on a 1970 454. I would like details.
Bob
 

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Sorry should of been more specific. I can’t find a tank here in Australia.i would buy one from the states but shipping is around $1000.
The exterior dimensions on 68-72 fuel tanks are identical. That 70 tank will fit in your 72 using the same mounting straps. You will have to use a vented gas cap unless you get a tank with vent pipes coming out of the front. 70 Chevelles destined for sale in CA had the additional vent tubes towards the top front of the tanks where Chevelles destined for the other states did not have the tank vents.
 
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