theres no reason why you couldnt, once you inderstand what you are doing

this is worth a little read, even though its to do with normally asperated YB's
http://www.amazon.co.uk/exec/obidos/...938591-5127948

http://www.amazon.co.uk/exec/obidos/...938591-5127948

that will give yo begining knowhow of how to build a half tidy engine! then you gotta learn what works with a yb, head gasket types, bolts, clearances and so on