I know that the rear leaf springs are longer on a 56 F100 than on the 53-55 (not sure about the 55 though). What I don't know is the distance between the rear axle centerline (measured at the middle of the bumpstop) and the front spring mount rivets. There are two rivets, 4 inches apart, that hold the spring mount to the frame (also two under the frame but those won't help in this case), I would like to know the distance between either of the rivets and the center of the axle. Thanks in advance...

BTW - If I could get multiple measurements from both the slant cab and the 56 then that would also put to rest the question about what section of the 56 leaf is longer...ahead of the axle or behind the axle.

 

I have a 55--------22" from the (front hanger)rear top rivet to the center of the axle. and 25" from the frt top rivet on the rear hanger Savvy?

 

Thanks. I have a TCI 4-link setup that was originally for an F1 but they told me the only difference was the length of the arms. I measured the same 22" to the rear rivet but the rivet holes are 4 inches apart making the front rivet measurement to be 26". Good info, thanks again.

 

So I made it out to my storage garage today and was able to measure my 53 and my 56 rear springs...both were the same. I don't have an F1 handy so I couldn't measure it. I know that the 56 springs are longer, now I know that the added length is all behind the axle. Here is a pic of what I am working with, it is a TCI 4-link that was advertised as being for a 48-51 F1...not the 53-56 F100. When I called TCI and asked what the difference was between the F1 and the F100 they told me that the length of the links were different. I mocked these "F1" arms up with the front mounting bracket and the rearend bracket and to my surprise they are the exact same dimensions as the stock 53-56 spring/axle setup.

 

I cannot give you the measurements for the rear leafs (5560), only the part numbers. F100 is C in the catalog.

Notice in the left pic that the 1953 & 1954 part number (TAAA-5560-C) is the same.

Notice in the right pic that B5C-5560-A ~ B5C-5560-B ~ B5C-5560-C are the same for both 1955 & 1956.

The only 1956 F100 specific rear spring is: B6C-5560-A .. 7 leaf progressive.

 

Thanks Bill, that's why I wrote in my original post that I wasn't sure about the 55. Lots of commonality between the 55 and 56, just not so much in the cab sheetmetal.