Back to your original questions from your original post before it got dilbeck'd on:
If you have the entire suspension and drivetrain from another car, and you have the know-how to weld it all into position, build your suspension mount points into your chassis and line it all up. Depending on where you end up mounting your engine and transmission, you can get all the measurements and take them to a competent driveshaft shop and they can build a driveshaft for you that will connect the transmission output to your rear end / differential.
If you have the entire suspension and drivetrain from another car, and you have the know-how to weld it all into position, build your suspension mount points into your chassis and line it all up. Depending on where you end up mounting your engine and transmission, you can get all the measurements and take them to a competent driveshaft shop and they can build a driveshaft for you that will connect the transmission output to your rear end / differential.