First Gas Tank swap - What do I need to know?

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1974PlymouthDuster

1974PlymouthDuster

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Hi guys - everyone has been able to throw in their $0.02 about the 70 Valiant sedan project. Appreciate all the input. A little more rust than I'd hoped for, but just a little Slant 6 Sedan for me to plow around town in.

Main driveability issue I have is a hole in the gas tank, presumably from rust and/or age, I can't fill it up past 1/4 tank, or it leaks from a high spot.

Already confirmed it's not the sender or gasket.

With such a critical item (gas), I decided to throw in a couple bucks for the tank project.

Purchased the decently reviewed Spectre gas tank from amazon. Full list of purchased items:

Gas Tank (includes lock ring)
squeek pad to cover on top of the gas tank, between body.
felt straps for strap squeeking
two new strap bolts (the bent L-ones)
two new metal straps
two oetiker hose clamps

Re-use old sender - it works, but going to give it a good cleaning.

I have tried to go through all resources to review the project piece by piece, and hoped to source all parts to do the job correctly.

My question for the crew is

#1 - Anything you wished someone told you before you did your first tank?
#2 - Any parts I'm missing?

Only item I need to find (I think?) is the filler grommet
http://www.classicindustries.com/mopar/parts/mf296.html
 
Keep the old lock ring and use it if it fits. Or at the very least compare the new to the old. The new ones seem to be thinner and won't seal the sending unit like they should.
 
Yup, re-use the old lock ring. I've also taken to "adjusting" the lock ring tabs/ramps with a pair of pliers so they apply more pressure, it makes it very obvious when it locks into place. I use a set of giant channel locks to turn the lock ring, makes it easy even with the modified lock ring tabs.

Also, I stopped using the gaskets that come with the new tank/lock ring. DMT makes them in house out of the same stuff as factory and the same thickness. I swear the new gaskets that come with the new tanks and sending units are thinner.

Here's the link to the DMT gasket

[ame="http://www.ebay.com/itm/DMT-Mopar-57-91-A-B-C-Body-Fuel-Lock-Ring-Sending-Unit-to-Tank-Seal-/360751319879?pt=Vintage_Car_Truck_Parts_Accessories&hash=item53fe744b47&vxp=mtr"]http://www.ebay.com/itm/DMT-Mopar-57-91-A-B-C-Body-Fuel-Lock-Ring-Sending-Unit-to-Tank-Seal-/360751319879?pt=Vintage_Car_Truck_Parts_Accessories&hash=item53fe744b47&vxp=mtr[/ame]

And definitely get a new filler neck grommet. Mandatory with a new tank really, you probably won't get the old one out in one piece. I had to replace mine even though I didn't change the tank, as it would leak when I went around corners with a full tank. DMT sells those too...

[ame="http://www.ebay.com/itm/DMT-Mopar-64-74-A-B-C-Body-Fuel-Filler-Gas-Tank-Tube-Grommet-/360653566137?pt=Vintage_Car_Truck_Parts_Accessories&hash=item53f8a0b0b9"]http://www.ebay.com/itm/DMT-Mopar-64-74-A-B-C-Body-Fuel-Filler-Gas-Tank-Tube-Grommet-/360653566137?pt=Vintage_Car_Truck_Parts_Accessories&hash=item53f8a0b0b9[/ame]

The only thing I'd do to the sender if it still works is change the filter sock on the end and make sure there's no fuel in the float. Anything more than that and you're asking for trouble, it doesn't seem like it takes much to stop them from working. At least every one I touch seems to stop working, maybe its just me. :violent1:

Here's the sock if you need a new one (you probably do...)
[ame="http://www.ebay.com/itm/Mopar-Fuel-Gas-Tank-Sending-Unit-Filter-Sock-NEW-/400537440793?pt=Vintage_Car_Truck_Parts_Accessories&hash=item5d41e45219&vxp=mtr"]http://www.ebay.com/itm/Mopar-Fuel-Gas-Tank-Sending-Unit-Filter-Sock-NEW-/400537440793?pt=Vintage_Car_Truck_Parts_Accessories&hash=item5d41e45219&vxp=mtr[/ame]

And when you're all done, fill the tank SLOOOOW. Nothing worse than filling the tank all the way up only to find out its leaking and having to siphon it all back out again when you can't stop the leak.
 
In my Duster project, the same leaky gas tank came up. I soldered the holes, used KBS tank coating to seal in the holes and give it an impervious coating. Then purchased a new sending unit. In hind sight, I should have just purchased a new tank like you did. It would have saved me lots of time. And do save the old lock ring. The new one didn't lock as well as the old one did and I even reused it.
 
And don't forget to clean the grounding strap on the sending unit to the tank for a good ground. Those get rusty too and a poor contact is guaranteed.
 
Wear safety glasses, disconnect the battery, don't smoke and have a fire extinguisher and safety equipment VERY handy.
 
Get some one to help hold the dam tank up with you.
after a few minutes it gets frustrating getting the filler tube in the Gasket!!!
Good luck.
Johnny!!!
 
If you still have caveman droplights with caveman bulbs, keep them far away and unplugged. Ask me why!
 
get the one in the car as empty as possible - if it has fuel in it and it tips at all, the weight shift will take it out of your hands quick! Did this with a tank in a 97 GMC 1500- about a half tank in it - thankfully I was doing it on the ground and it didn't have far to fall...
 
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