A friend of mine has a 2wd Explorer and wants to turn it into a 4wd. He has access to a 4wd B2 for little money and wants to know if the driveline parts, t-case, front diff, etc... are interchangeable. This begs the quetsion "why not just use the B2?" He wants a four door 4wd vehicle. So, will the parts swap and is this a realistic swap?