I will throw you another twist...Gensis is shipping the new 427SO block...now its built on the same setup as the originals but they improved on some of the weak points but it still uses the SO setup of old.
Now they are suppost to be shipping the aluminum block in about 2 months.....it is cast the same as the iron block.
Then you have a real aluminum 427 cu in SO.
By the way most of us with the boat anchor don't have a 427 anyway..........mine is like 433 after they bore it out
Matt