Transfer. Box help

[Mumpy]

I wonder if you can help

I have a Kzn185 ssrg with a jumpy 1st gear. I've procured a r151f gearbox complete with transfer box.
My new transfer box has three not four positions. Does it matter?
What donor vehicle would have had a three position transfer box?
Can I swap the transfer boxes over?
Is it best to split the transfer box from gearbox before removing the gearbox. Bearing in mind i'm doing this from the ground?
Where is the transfer box model no located on the box?

Many thanks in advance

[The Boo Crew]

What is the r151f out of? I dont think its a surf box. I assume its manual 4runner? or later pick up

[NiftyNev]

The second generation Surf had the R151 and R150 gearboxes. Other vehicles also, but there may be differences with boxes out of the other models.

Nev.

[budweiser]

How do I know which box is fitted?
would the chassis plate tell?