Short beds could also have flex-o-matic rear suspension. My 68 swb has them stock.

 

does it really matter if i put the 5 leaf pack or the 6 leaf pack if i have the right length u bolts? the only thing that i think would be different is maybe the height of the truck.

 

Well there's a 5/16" difference on pack thickness between the springs and a 3/4" arch difference so the 5/1 will sit a little higher due to the strength of the spring. As far as u bolts you should always replace them when replacing leaf springs. Now there's actually a different 4/1 which came out in 72 which has a 1650 capacity which would work as well. Again, make sure you verify either you have the EZ Ride shackle or measure the springs to ensure a proper fit. For whoever asked about the books I used they're called SRI which is the spring data manuals for every spring ever built since 1950 and according to this book it says F100, EZ Ride Shackle Long WB and F100, Std. Shackle Short WB and lists the springs seperately for some reason.

 

Ok. According to my Ford Truck parts book, there are four ways to look up spring part numbers (found on p. 2, sec. 55):

1) Use the Truck Specification List (TSL)
2) Use the spring stamping number
3) Use the rear suspension model application chart
4) Use the rear spring size chart


Using the rear suspension model application chart (p. 18, sec. 55), I find that there are three possibilities that are common to 67-72 F100 (also common to other models, dependent upon axles):

1) C5TZ 5560-A (950 lb capacity)
2) C8TZ 5560-A (1250 lb capacity)
3) C8TZ 5560-C (1650 lb capacity)


Referring to the spring size chart (pp 48-49, sec 55), the dimensions are:

1) C5TZ 5560-A -- 2.25 x 24 x 28
2) C8TZ 5560-A -- 2.25 x 24 x 32
3) C8TZ 5560-C -- 2.25 x 24 x 32


Now, I can't be 100% sure, but based on many years experience working on trucks (light-duty AND heavy-duty), I have to assume that:

1) Since there is no reference to wheelbase in the parts book, the spring part numbers are based on weight and length alone
2) Since Flex-O-Matic should be the heavier duty suspension, the longer (24 x 32) springs are for a truck with Flex-O-Matic
3) choochoof150 says his 68 SWB truck has Flex-O-Matic, so I assume that is the first year for that option, based on what I can find
4) Since the longer springs are C8TZ part numbers, they would correspond with the release date of the Flex-O-Matic suspension
5) Since the longer springs and Flex-O-Matic dates coincide, the longer springs are used with the Flex-O-Matic suspension.
6) According to Ford sales literature, the Flex-O-Matic springs are 4" longer than the standard springs used on "conventional" suspensions


These assumptions and the accompanying data are by no means complete. There are other part numbers that I did not include, as they really didn't meet the criteria of this discussion. In 72, the method of rating the spring capacity changed, so the data shown here is not consistent with the later rating method (as shown in the parts book), although the 72's do use some of the same part numbers.

Does anybody have any other explanation and/or Ford application data?

I'm not trying to be a smart a$$, but I'd really like to know whether or not this is correct.

 

Hello all. Newbie here, but a long time lurker around the forums.
boo-yaa138- I have the springs you want. Earlier this week, I pulled a set of Flex-o-matic springs from a 70 LWB F250 Camper Special in pretty decent shape. The engine was blown & a bit of rust. Shame it's heading for the crusher.
They are the 4/1 stack. Really Beefy springs. I was wanting to put them on my 79 F100, but I didn't measure them correctly. They will not work on the 73-79 frames. Boy do I feel silly after all that work. It was no easy task to get them, not to mention 98 degrees w/heat index of 110. Anyway, I'd be willing to part with them for a reasonable price plus shipping if you are interested. I'll check back here on the forum or you can shoot me an email if ya like & we'll talk. I'd really like to see someone use them for their intended purpose.
BTW- Thanks to all for the useful info I've gotten from you.

 

Will the GVW rating tell which capacity springs are in the rear? (C8TZ 5560-A, C8TZ 5560-C)
My '72 short bed has the H2, 3600 lb. axle, 9 3/8", 31 spline, Flex-O springs, 5000 GVW.

 

I don't see anything in the parts manual that cross-references GVW to the spring part numbers until 72, but that doesn't mean it isn't there.

You should be able to determine the part number by the number of leaves in the springs.

C8TZ 5560-A has 5 leaves (5000 GVW for 72)
C8TZ 5560-C has 6 leaves (5500 GVW for 72)

 

The main leaf has the specific Ford ID number for the spring pack stamped on it in the vicinity of the eyebolt.

Post what it is.

 

Only 5 leaves total for an F250,especially one like a Camper Special,which i assume would be a rather heavy GVW model,seems a little strange? I would have expected 7 or 8 leaves?

 

The Ford parts catalog shows a 6-leaf main spring on ALL F-250 4x2 models from 68-72.

The GVW ratings shown for 72 range from 6200 to 8100 pounds.

Prior to 68, they could have 6, 7, 8, 10 or 11 leaves.

 

iggybob44- I agree about assuming there would be a larger stack on the Camper Specials. But there was another Camper Special,a '71 LWB, next to the one I robbed the springs from and it had the exact same 4/1 set up. I discovered yesterday that I can remove the Flex plate & mount directly to the eyes. So this will mount on my '79. Just got to find the correct bushings. The front bolt was 15/16 & the rear was 7/8. That seems strange to me because both of my bolts on the 79 are 7/8. Anybody know where I can find the bushing for 15/16 bolt. None of my local parts dealers have one.

boo-yaa138- Sorry, looks like I will be using these springs after all. Good luck w/your search.


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Bill,

Question for you. Do you know what size U-Bolts were used to attach to a 5 plate leaf spring and how they were attached; i.e. around the axle with mounting plate or other option?

Thanks for the help,

Lax

 

I'm not Bill but I'll help. I need more info though. There are choices. If you have auxiliary springs it's the 1st choice. If you don't then I need to know with or without a factory locking rear end. 2nd and 3rd choices.

 

Jeff,

Thanks. The ones I was going to buy are from here: Leaf Springs 1942 - 1972 Ford F100
the 950b 5leaf for my year.

Only thing is I don't have my truck yet - its still being shipped - I should have it by tomorrow. I am trying to get everything ahead of time so can make this a quick restoration or at least a shorter one. This being said I was trying to figure out what type of Ubolt and mounting plate if any I needed prior to. I wasn't planning on changing anything but the springs everything would be as original as possible.

Hope this helps - thanks again

 

Not really. All you did was confuse me Buddy. Why worry about the plates? Reuse the ones on it. And on the U-bolts I would still need the above info. With or without auxiliary springs being used and which rear end. The axle tubes that the u-bolts go around are a different size diameter between an open rear end (9") and a locking (Dana). Note. A local leaf spring company can custom build you u-bolts of whatever size and diameter you would need. Sounds like you may be putting something on that truck that it doesn't have on it now. Or that my Ford slide may list.