gas tank is giving me fits.....


I wish I didn't have all of these balls in the air
15 Year Member
Dec 6, 2005
Marietta, Ga
Just a quick question for everyone. I got a gas tank from another II and am having problems getting it into postion. It seems to be interfering on the thick side of the tank. I can get within about an inch of both strap bolts, but I am not having luck getting closer than that. So, my question is, could there be a difference in tanks from model to model or year to year? I didn't think there was, but maybe I am wrong. The only other variable to this equation is that I made a couple strap bolts....maybe they are not long enough? They stick out somewhere around 2", and by the Hayne's manual I have sitting here, the bolt stick out should be somewhere between 1.87"-2.12" after the tank is mounted. Could someone also let me know what the original lengths are and from where you measured? I have to figure something out here....getting frustrated!!! :bang:
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:D It may be possible that you have a larger tank than you first had. If your car was a 4 or 6 cyl it had a 13 gal tank on it. The tank you might have now could be for a v-8 or the extended range option from another car, either way you will now need the straps from the car it came off of. Hope that helps.:shrug:
All the tanks are 13 gallon, the only thing that added capacity was the small fender tank on V8 cars.

What year is your II and what year is the tank? The shapes did change slight somewere along the line and I don't believe they interchange.
My car is a 78. As far as what year the tank is from I have no idea. I got it from a guy parting out a car along with a windshield for a great price. I am going to try to get some pics later on of what I am dealing with so everyone can see.
I have a couple pics of what I am running into. The top of the tank is just too wide. Everything else is about right. Should I just try to find a 78 and get the tank from it, or get a bfh and "modify" it to fit? If anyone has a tank from a 78 and would like this one, I can do that too. There are already some dents in the bottom of the tank now. Let me know what you guys think.
Is there anyone who has tried to use a fox mustang tank? I would like to fill the back end up anyways and that would do the trick. they are shaped somewhat similarly, just longer on the thin end. would it have to be an early fox tank, seeing how they were carbureted? Just a thought since I can't seem to find anyone who makes a replacement.
Is there anyone who has tried to use a fox mustang tank? I would like to fill the back end up anyways and that would do the trick. they are shaped somewhat similarly, just longer on the thin end. would it have to be an early fox tank, seeing how they were carbureted? Just a thought since I can't seem to find anyone who makes a replacement.

I think the filler neck for a Fox is on the passenger side, so it may not work unless you want to do some bodywork to move the II filler neck to that side.
Yes, I have thought about a fuel cell. The only drawback is price basically, and I would like to keep it looking like it would originally be that way too. A Fox body fuel tank would fit the bill rather nicely, and there are replacements for them. I am going to pick one up either this weekend or next from a scrapyard just to see. I can get it for $50 and maybe I can make it work. If not, I can just scrap it back and be out the $50. Looking at pictures of them online and in the Mustangs Unlimited catalog, I think about the only thing I would have to fab would be the pick up location. Close up the actual front side and move it to the actual back of the tank. Then install the tank backwards and fab a new strap location or 2. That is what I am thinking for now, but when I get it I am sure other things will pop up....time will tell!!
I believe Sal's right, the II underwent chassis underbody changes mid-77. I pulled factory dual exaust, hangars and all, off a '76 II and went to install it under my '78 and nothing lined up to any of the bolt locations, not even close. However, all the bends were still just fine and it fit ok, provided you have to re-do all the mounting points aft of the tranny.
I've also seen a exaust pipe snaked alongside a II tank on the driver's side 9for a dual exh setup)but on my '78, I tried and it was a definate no-go. So there must be something significant about those '78 tanks....:shrug:
:D I have the duals and they stick out in front of the rears. I am going to talk to my body shop bud cause I have sort of a sick idea. I want to take a drop in tank,ie 65-66 or 69 and put in in there and have the neck out the rear and close the side panel, then put the filler neck between the taillights. I cant use the spare area any more since I am running 15's so i thought what the he++.If I can put in the 69 this will really give me a larger tank.(22 gal) and with the theme on the car that I want, it fits perfectly.:jaw:
Yeah i had tossed that idea around too. That area that the lic plate resides in is really ugly without the plate. A fella would have to rework the steel and make it a little more appealing before adding a fuel filler and cap.....unless you go with a drop down lic plate deal like the 67-8 Cougars used. That'd be trick.
But I'm going to put my batt cut off switch behind the plate, and just remove the plate when I'm at the track. I really don't care for those cut off switches hanging out all over the body... but the NHRA does...:rolleyes: I figure my idea meets it in the middle.:nice:
:D we spoke yesterday (my body shop bud and I ) he said it would be no problem. as far as the trunk lock goes, we take out the lock cylinder and use a remote. the ford letters are coming off anyway. he had also suggested a fuel cell custon built for the trunk but i dont want to go that way.I have a special gas cap I want to use on this and I need it to come out the back panel. I will let ya know how it goes.:jaw:
Well, I got the Fox tank, and here is what I have run into so far with it. The tank is out of a later fuel injected car, so the pick up and gauge sending unit are on the top of the tank. Those had to be closed up and the original pick up from the II installed on the bottom of the tank, on the actual backside of the tank. The tank does fit when reversed from its original position in the Fox bodies. In this tank, there is a slight hump in the center of the thinner part that allows it to rock on the spare tire well. I am going to try to use some 1 inch square tubing to give it 4 resting points when I figure out what I am going to do about straps. Finally, the filler hole in the Fox tank that I have is about 1/4 inch smaller than the II filler hole. I cut this out of both tanks and welded the II filler hole into this tank. A guy could probably fab something to use the Fox filler tube I suppose, especially if you have the extended tank in the fender as I do. I am going to try to get the straps figured out this week sometime, so when I do, I'll get some pics posted.
My plans for the trunk will be to remove the stock tank, cut out the stock spare tire well, weld in a flat sheet and install a 16 gal cell centered in the floor. This will free up the space on each side to run the dual 3" pipes, and mount the mufflers on edge next to each lower trunk box, so they fit right up in there, out of view.
I'll mount a fox body remote trunk release in the glovebox, remove the stock deck lid springs, and use two low pressure lift shocks, so when the button is hit, the trunk opens slowly and smoothly, and allows access to the fuel fill on the cell.
And no more ugly fuel fill hole ruining the body lines of the quarterpanel. :D
Yeah I'd like to loose the side-by-side 3" dual pipes I have now for equally spaced ones and was looking into a fuel cell to get them there. However, I'd sure like to see some pics of the Fox tank installed. Could be the ticket. :shrug: Either way, that spare tire well is more or less useless to me in that car too, so might as well make use of the space otherwise. :nice:
Well, I have the tank installed. I got some scrap steel at work and sheared it to use as straps. I used 2 lag bolts and 2 button head cap screws where I mounted them. I do have a slight clearance problem on the passenger side, but as long as my springs don't lay flat during acceleration should,t be too big of a problem. The tank does fill in rather nicely though. The only asthetic thing is the hump in the center of the tank which was meant for the pumpkin in the Fox bodies is now in the center of the rear of my car. Otherwise, I don't think it looks too I just hope my welds don't leak!! :shrug: