Hi,
Is the engine block the same on all cast-iron new MP hemi blocks no diffrence just the bore size and rough/finish bore?

They use the same iron engine block for the different bores...?

this one is regular bores and block non siamese (think they are pretty much all gone)
http://chucker54.stores.yahoo.net/mope440bl.html

The siamese blocks have no water between the cylinders thus will accept big bores.
http://chucker54.stores.yahoo.net/blcairsi.html

These may be disappearing too!

The part in the first Mancini link has not been for sale through MP for six years. If I remember the story correctly mancini had a bunch of old stock at one point.

The parts in the second Maninci link are "the new ones", they aren't disappearing, and to answer the original question yes they are based on a common casting. The "new"(2007: not really new at all) Wedge blocks are also based on the same casting.