what is the difference between different turbos different cars? they are all set up the same arent they? like could you use a diesel turvo on a sbc or a nissan turbo on an amc stright 6???

There is a lot of difference. You must size the turbo correctly for different applications. Your engine is capable of consuming so many lbs of air per minute. You must plot this out. They have compressor maps to show the efficiencys of different compressors and if your not in the correct efficiency your turbo will not perform well.
I suggest you do more research or get a kit that is designed for your engine and performance goals.