Gas Tank Options For A MII

LILCBRA said:

If I remember correctly there was a slight change to the top of the tank to accommodate for something. I know the early tanks don't fit the later cars though, I tried since the tank in my 77 was full of pinholes on top and I had a 76 parts car that I tried to swap from. From there I think there are only 2 - 3 options. 1st one is probably the most expensive as you've pointed out - find a replacement. A quick Google search revealed one through PartsGeek.com here. Another option is to swap in a fuel cell, but that may be just as expensive and most likely less practical, depending on what you could come up with. The third option is what I did way back when - the Fox cars use a tank with a similar shape but required modifications to the car as well as the tank. I have a thread in the stickies under the tech link: http://www.stangnet.com/mustang-forums/threads/fox-fuel-tank-in-a-ii.820975/

I also have a short YouTube video that I tried to illustrate what all needs done.
That path required welding on the fuel tank. Be careful if you try this on a used tank as I did, but I didn't have any problems. I got my tank from a salvage yard, but there are plenty of options for new. Mine was from a fuel injected car, but I kind of wonder if you were to get one made for an early non-EFI car, say a 79, if the filler tube would work and you wouldn't have to really do much to install the II's pickup. Those can be purchased new from LMR. They have 2 options for non-EFI, the early 79-81 and the 81-86. You could also opt to install the later tanks and just use a Fox pickup and pump in conjunction with a fuel pressure regulator, but IIRC the fuel level sender has different ohms settings as compared to the II so your gauge might not work properly.

I guess there's a 4th option that I know has been done, but that requires even more modifications to the car: cut the floor from the hatch/trunk and install an early Mustang tank. That requires relocating the filler, using a flip down license plate and sealing off the original filler.



You are correct, the 74s had the filler neck located lower on the quarter than the 75-78 cars, but to my knowledge the tanks are the same from 74-76.

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LILCBRA said:

If you chose to go with a Fox tank and Fox electric pump the sensor could be added at a later date. The resistance range for those sending units are 145 Ohms Full 22 Ohms Empty as referenced from LMR's site here. The II's resistance range is less as quoted from another old thread here:



I guess it would depend on your budget and what you could find through a salvage yard or through places like Ebay and Craigslist/Marketplace, but the best solution is probably going ahead and spending the ~$175-200 on a new replacement tank instead of going with a different style (fuel cell, Fox tank, etc....). There were no replacement tanks available when I did mine, they are a relatively recent offering. But given the supporting pieces and extra work, the others will most likely keep increasing the total amount of money involved. So I guess I retract my statement on this path probably being the most expensive UNLESS you're able to find a Fox tank in a salvage yard for ~$50..... but even then it might be a wash. I will add, though, that if you were to EVER decide to install fuel injection, a Fox tank gives you a couple options more easily than a stock tank.

Side note: if you happen to have Amazon Prime and can take advantage of free shipping, you can get a new tank for $166 and some change....

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