I had already considered the ZF and I would love to get one but I have to take what the junk yards are offering and the one that had a ford 4x4 trans did not knot which it was

 

If I remember, the two trannys are pretty easy to tell apart. The m5od has a square patterned case and a zf5 has a diamond pattern...that'll make sense when you see them. If you're looking at doing gears and a tranny swap, a parts truck might be best, if you have room for one. I say this because sometimes its the little things, like front driveshafts, that can be a pain to track down.Also, something to keep in mind about tranny swaps is your speedo cable. Up to '91(?) They used a tranny mounted sensor, and 92+ (I think) used a rear axle mounted sensor.

 

So , have you figured out what gears you have yet?

 

I haven't figured out the ratio yet but I think I am going to table that idea for now anyway. After some minor work I did to the truck it runs much better and the diff gearing doesn't seem as big of a problem. I still want to do the ZF S5 tranny swap and I want to get the truck back to Fuel injection. I have found a 97 Explorer 5.0 engine with all of the wiring and the computer for $750 so I may purchase that with my tax return and build a new drive train from there.

Are there any special considerations I need to account for with swapping to the ZF? I know the bell housing and transfer case will work but what about any mounts and the rear driveshaft?