You'll need the extension housing from a '92-'96 transfer case or the speedometer gear assembly from a pre '92 to plug the hole.

 

Sounds like I will be cutting one off at the cable in the salvage yard. Are they the same fit for all the F-150s 1988-1991 no matter what transmission or transfer case if applicable?

 

Go to Napa and get a frost plug in the correct diameter and gently tap it in to place. Use some Locktite if it doesn't fit very tight.

 

I believe they're all the same back into the early '80s. 2wd, 4wd, doesn't matter. A brass plug would work as kc0rey suggested if you can find one of the proper diameter.

 

Here is the speedo gear hole. I think AZ sells a rubber ring brass plug that will fit it. The more you tighten it down the more it smashes the rubber and expands it.
Does anyone know what transfer case this is. I'm afraid ORA was thr only thing I noticed marked on it. It kinda to me looks like a BW1356 manual shift. I'm of the understanding those were pretty popular.

 

If its slip yoke its 1356 those were only ones with slip yoke and the yoke is hard as hell to find at least here in ms shop had to special order it from virgina

 

OK slip yoke vs what? Define the difference. Sorry for thr ignorance. It does not have a flat disc at the end where a flat piece with a yoke would bolt to it and have a U joint, it has a splined shaft and a Yoke that goes streight onto the tailshaft. That yoke is still connected to the drive shaft via the U joint. No bolt holds the yoke onto the back of the transfer case. Does that mean slip yoke since it slips on and no nut holds it in place? I have that whole rear shaft, i will probably just have to cut it.
My current truck is a 2 piece driveshaft. I have an ext cab 2wd, short bed. The donor was a reg cab short bed 4wd.

 

The slip yoke just slips in and out hence the "slip yoke" just line up the guide splines and slide yoke and drive shaft in and bolt rear u-joint to real axle

 

Ditch the two piece, probably doesn't use two piece anyways. Get rid of the center support bracket and have a new driveshaft made.

 

And to get the u-joint out of the slip you use pliers to clamp those springs then use a hammer and socket to knock the heads off, when you hammer the top the bottom comes out ten flip and repeat.