4wd diff questions for 2wd swap

I have some bad noises coming from my 2wd diff and have a spare 4wd axle. will the 4wd diff bolt in to the 2wd axle housing? what is the gearing on the 4wd diff?(just wondering) also what are the wires coming out of the 4wd diff for? any input would help greatly because my 2wd is the daily driver!!

Technically. it is the same housing as the 2600 2wd, but it isn't a bolt in replacement. You will need to cut the spring perch off the top of the axle tubes and weld them onto the bottom. The gear ratio is lower(4.30) than the 2wd unit(3.73), so your speedo will read faster than actual. The wires are most likely for anti-lock brake sensor.
http://www.mazdatrucking.com/B2200/Differential_Swap.html

talking about the third member not the whole axle itself

My apologies. The 3'rd member will interchange, but if it does have an anti-lock ring, the opening in the housing may need to be clearanced to get it in.

its ok saw you link good info thanks