400 to 451 stroker what year is best block

I've never had a bad 400 block and I've had plenty. Those famed "230" blocks are rare as hens teeth and you could cut your state deficit in half with one! I've got 2 out of motorhomes and one out of a fury and looking at the webbing and the sonic sheet from the machine shop (Kendricks Speed here in S.A.) they seem identical.