Frame X-Member Q: What's needed to install a rear fuel tank?

[FuzzFace2]

I think it is the angle the picture was taken.
If you look at the right rail you can just make out bend up and maybe on the left?
(cross your eyes  )
Dave ----

[mat in tn]

it goes a little further than that. in the first picture of the refinished frame, you can see all of the 2.5" holes along the mid-section. this is the lightweight frame used on the f100 and f150 in 1980/81. some call it the swiss cheese frame. great for light duty. I cannot see whether the other is the same or not but by 82 this was phased out. my 82 f100 has the standardized frame without the weight reduction holes. one of the things about the lighter frame was the extra stamping offsets to add stiffness the same way corrugated style lines add "spine" to fenders and doors.

[Gary Lewis]

FuzzFace2 wrote

I think it is the angle the picture was taken.
If you look at the right rail you can just make out bend up and maybe on the left?
(cross your eyes  )
Dave ----

I agree.  I think I can see the bends in both places on both frames.

But, we have a new page: Documentation/Suspension & Steering/Frames.  And there you'll find the catalog listing for all the frames.  And here are some findings for part numbers of frames:

1980 F150 2WD: E2TZ 5005-N

1981 F150 4WD exc H/D: E2TZ 5005-N

So Dave's truck and Dad's truck should have the same frame.  However, as that is a 1982 frame given the "E2" then it is possible that when they rolled out of the factory they had different frames.  But I doubt it.

[salans7]

FuzzFace2 wrote

Are you sure on that?

I updated the post. I wrote it fast and didn't think to add that the parts truck was a Styleside and that's what I was referring to.

[Bronco638]

I completely forgot that the pic of the "non-rear tank" truck was from this site: LINK

It's an '80 F-150 4X4 and the post was from July of 2020. So, it should have the "Swiss cheese" frame.

And, yeah, if I squint/cross my eyes, like Dave suggested, I can see the "kick-ups" on that rusty frame. So, I guess I just chose a bad picture to illustrate my question.

[85lebaront2]

If it will help, here are some pictures of Darth's frame, keep in mind this is the polar opposite of the light weight frame, an F350 crew cab dual rear wheel truck.
Looking forward cross member is where the front of the tank fits.

Right side of frame in rear tank area.

Right side of tank area looking down.

Inside of left frame rail

Tank installed from left side.

[Bronco638]

Gary, is there a way to determine on which truck frames the cross member in question might be found? I saw a '78 F-250 on FB Marketplace that seems to have the correct cross member (that I need). I knew that the Bullnose and Bricknose frames are pretty much the same but wasn't aware that the previous generation of F-Series trucks might also be potential donors, too.

[Gary Lewis]

Have you looked at our new page at: Documentation/Suspension & Steering/Frames?  That page shows the part numbers for all frames from 1980 through 1989, and I've highlighted the applications that use E2TZ-N, which is the same as Dad's frame and should have that cross member.

[Tarheel Blue]

I simply used the rear crossmember from a junker truck as the front crossmember in front of the Bronco 33 gal tank  installed. VERY easy!

[Bronco638]

Hey Gary, yes, I've reviewed that page. I was asking about earlier trucks; 1973-79. Is there a way to determine if that cross-member is the same on those trucks? If so, it gives me a bigger chance of finding something close(r) to home.

[Bronco638]

I would prefer to use the correct part. My issue is that there aren't a whole lot of these trucks in northern Illinois. They rotted away years ago or have been crushed.

[Gary Lewis]

I really cannot say because all I know is part numbers, and I can't tell from a part number what the difference is.  However, I can say that since the "E2" bit of E2TZ means that it was designed in 1982, that it is fair to say that Ford changed the crossmember somehow then.

And, I've heard that the frames from the 1979 and earlier trucks were quite different than the Bullnose frames, although I don't have any proof of that.

So I think it is unlikely that the 1979 and earlier parts will fit your truck.

[Bronco638]

Gary Lewis wrote

So I think it is unlikely that the 1979 and earlier parts will fit your truck.

That's kind of what I thought. Thanks.