250/350 Rear end difference/Identification

[Silver91Hatch]

Well I went to a buddy's house and he told me he had either a F-250 or 350 rear end that I could have if I just got it out of his way. I took a look and its a 10.25" with 3.55's and I am wanting to swap my 4.10's out for a little more highway friendlier gear. My question is what are the rear end differences between a 250 srw and a 350 drw rear? It has long studs, and the tag says its a 10.2 so I am hoping I can swap the entire rear end into my rollback, if it won't work then I will do a gear swap...

 

[Agnem]

I know the dually rears are different, but if it is a single rear wheel, there really is no difference. Ford uses a 1 ton axle on their 3/4 ton trucks, unlike Chevy which has a different axle for each.

 

[J D Recovery]

Is the srw shorter than the drw?

 

[Jake S.]

In your 86 you might have a dana axle. Not sure when ford went to a sterling for duals. For the width, measure backing plate to backing plate. If your roll back is a cab-chassis, the frame is narrower(34inch comp to 37.5), and the spring mounts are too.

 

[Silver91Hatch]

The 86 has a Ford/Sterling rear. My rollback is a chassis/cab but the truck that the new rearend came from was a work body truck, so it was most likely a chassis cab also. I will measure the spring pads and total width, I am mainly worried about the axles/hubs/brakes and making sure that the dually wheels will work with it.

 

[Jake S.]

Drw have 12x3.5 shoes, srw has 12x3 otherwise the only diff. that I can think of is width.

 

[towcat]

srw/drw are different in the offset in the drum to acomodate the drw.
commercial drw axle is the shortest, pickup srw is in the middle, pickup drw is the longest.


silver 91-
you won't like the performance with the 3.55's on your rollback if you hit any hill.

 

[Silver91Hatch]

silver 91-
you won't like the performance with the 3.55's on your rollback if you hit any hill.

Well it kinda sucks now only being able to run 55-60. I have lower gears in my transmission, I can downshift to 3rd for a hill, I can't go any higher with the trans and a GV or a gear splitter is $$$. This is free.

But on another note, I mostly drive less than 5-6 miles to the dragstrip but I also drive to another track and there are some big hills to both and it never leave 60 loaded.