block identification concern

Guys we will probably need your help as we will both be looking to get good engine blocks, 400 for me and 440 for the owner of this thread :)
We need to make nice, fresh 470 out of 400 and 496 out of 440.
Challenge is to get them from honest seller that won't make us ship piece of crap half way across the world only to find out we got junk after spending few hundred $$ for shipping.

Trying to avoid the problem led to this thread starting and photos posted for identification :)

We will post an ad for this soon I guess.