LongBlock = Block with complete head.
ShortBlock = No Head, all internal rotating parts included.
Try this,,, go to your local Schucks/Kragen/Thrifty auto parts. Ask for a BMW long block. Since their normal rebuilders can't supply them they usually have a specialty shop do it. The Schucks auto supply near me will even tell you who the rebuilder is. AND best of all,,, they give you a decent 36000 mile warrantee. Then!!! Buy it on a cred card that doubles the warrantee.
AMEX and MC have some sweet deals and they mostly havn't caught on to this yet...
Dave