Any particular turbo or powerstroke turbo that your interested in?
What brand info are you wanting. Most of us here can tell you a good bit of info on turbos.
If you want something more formal than forum talk:
http://www.fusca.net/wp-content/uploads/Maximum_boost.pdf
Garret is actually an easy one to learn about. Their part number tells you everything you'd want to know, http://garrettbyhoneywell.com/products/turbo-identification/ . R at the end is ball bearing, gtx is a high flow comp wheel. Is this the info you're wanting?
Borg Warner is s4(frame size) 75 (inducer size)