These spring brackets are designed to mount onto 1977.5-1979 Ford F250 4wd trucks and allow you to install 2017+ Super Duty leaf springs, and Skyjacker FR173S in particular. They are self locating off off of oem rivet holes, and require drilling a total of 8 new holes with a 7/16 drill bit.

Before you order, please know that I am coming out with a set of brackets meant to install F150 Raptor lift springs.
 
These work well with either OEM axles or 2005+ SD axles.
 
2017 Super Duty leaf springs are a massive 65" eyelet to eyelet. The ride quality with these springs are just amazing. Very smooth and soft, with excellent weight handling. The oem springs had a good amount of variance in weight capacity and ride quality, so I consider Skyjacker FR173S the only way to go.

I have a page with hgh resolution pictures of these parts installed in a 1978 F250 frame here, scroll towards the bottom:

https://www.battlebornbrakes.com/f26a-gallery
 
 
Axle Perches:
All 37.5" wide rear frame applications can use these brackets along with modern super duty 10.5 sterling axles with no cutting or welding of perches. This is most all singly cab and crew cab applications.
All 34" wide rear frames- which shuold be all crew cabs- require cutting and welding of perches to move them closer together. 
 
This listing includes all four brackets, enough to swap out both of your rear springs for super duty springs. 16 new 7/16" grade 8 bolts and all metal lock nuts are included!
 
 
You will need to separately purchase these things:
-Rear 2017+ Super Duty leaf springs, Skyjacker FR173S in particular
-Leaf Spring plate- the 2017 super duty trucks have the U bolt pointed downward but you can mount U bolts in the traditional upward fashion with a basic 3/8" thick steel plate that I sell
-Leaf Spring Shackles for rear of leaf spring. These brackets are specifcally designed to accpet 2008-2016 rear shackles, which are cheaper and easier to source.
-U Bolts- upgrade to 5/8"! (see Superlift 11604 for example, but the length depends on your lift blocks) no lift block = about a 9" U bolt. longer is ok too. 
-Pair of 5/8" x 5" bolts/lock nuts and 7/8" x 5" bolts/lock nuts to mount springs to thee brackets
-7/16" Drill bit