2wd & 4wd crossmember differences

[Lift]

I have a 302 in my 1983 ranger and its 2wd and im starting to think it would be pretty badass to convert it to 4x4. My father already has a transfer case he was going to use in his jeep for his project but he decided he wanted a different one, so i have a transfer case i can use, i would need radius arms, axle, drivelines, and a few other little things and maybe some fabrication. I can get most of the stuff i need through my local junk yard fairly cheap, and is it possible i can make my own radius arms? or lengthen stock ones from whatever i get my axle off of?

ANYWAYS, I have done some reading here and there and some people are saying you need a different engine crossmember?? What i read tho was that the 4x4 crossmembers stick down to much and hit the axle unless you have a 6" lift or more. But what about the 2wd crossmember? why would i need to swap it for the 4x4 crossmember? Is this only a concern when using a D35? I plan on lifting it but, Even if i didnt lift it what is the difference between the two crossmembers, also is the frame different? Would i be able to do the sas with the stock 2wd crossmember? I'm a visual type of guy so pictures would just explain soo much to me

Thanks and i appreciate any information about the crossmember and 4wd conversion.