Rear differential swap

NEED HELP!!! I have a '61 Econoline pIckup, 144 engine, 3 speed, with a 7.25 rear diff. I want to install a 9" from a ''66 E van that has an automatic tranny. Can anyone tell me what I'll need to do for a drive shaft? Will the brakes swap out and what gear might the 9" currently have? Thanks

I was just looking at my 66 rearend tonight and was going to swap the one from my 67 into the 66 (both are 9" rears). I noticed that both vans have 2 1/4 inch wide springs. What are the springs on your 61? You may need to take the leafs as well if your 61 are 2 inch wide. as for the drive shaft, I am not sure...Are you taking the drivetrane out of the 66 with the auto trans as well as the rearend? If so, get the new motor into place and the trans mount in and go from there. May also want to concider a full cross member that the 66 should have with it and put that in as well. The 2 little arms in the 61 are not very strong and will bend when put under to many heavy loads. Once you have that then it's just a matter of bolting in the rear and seeing if the drive shaft that your donor van has and see if it fits. If not, take it to a machine shop and have them make a new one using your drive shaft ends and you should be good to go. Not knowing what motor and trans you want to use makes it tough to say for sure what will be needed. I'm sure those that no more will chime in...stay tuned.

The rear axle is a direct bolt in. The emergency cable is different but just use the cable from the 7" rear. Remove them from the backing plates and install them in the 9" plates. Your 61 rear is actually called a 7" All 144's used the 7. The 170's got the 7.25 rears. They look the same except for the pinion shaft is one inch longer on the 7.25. A drive shaft is a whole new ball game. Ford never made a shaft with the slip yoke on the front that the 61-62 trans has and a nine inch rear yoke. The did make one with the small u-joint on the front and the large u-joint on the rear. These were in 63-64 Heavy Duty only and are hard to find. I think you can take a slip yoke off the little shaft and put it on the small u-joint on this shaft if you can find one. Another option is the replace the 61-62 trans with the 63-64 top loader 3 speed trans. This will bolt into the 61's mounts. It also has the small yoke on the rear of it but it can be replaced with a larger yoke from the 65-67 top loader three speed. This will allow you to use the common 65-67 driveshaft. I've never done this swap but I'm told it all works. I can double check it all for you before you go searching for parts. You can have a drive shaft shop custom make a shaft also. If you are looking to put an auto trans in that's a whole nother can of worms. The nine inch rears were offered with 3.00, 3.50, 4.11, and 4.56 gears sets with 3.00 being the most common. 7 and 7.25 came with 3.50 and 4.00 gears. If your nine doesn't have the gears you want they can easily be swapped for with another chunk with better gears. Just make sure it's 28 spline.

HTH
Duane in Tennessee